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  1. quotes

    Hedge Needs - Which Model is Best to use?

    That sounds like that I go back to the times before Black-Scholes...
  2. quotes

    Hedge Needs - Which Model is Best to use?

    anyone with new idea?
  3. quotes

    Risk Neutral Pricing = Martingale Pricing?

    Thanks everyone. Here is my answer - straight forward derivation without risk-neutral measure http://ssrn.com/abstract=2397010
  4. quotes

    Chaos Theory and Financial Markets

    Many build algorithm trading only on MACD.
  5. quotes

    Illustration on Martingale Pricing

    http://ssrn.com/abstract=2397010
  6. quotes

    Hedge Needs - Which Model is Best to use?

    The market consisting of only the OTC market - each option underwriter retails their options to clients by contract.
  7. quotes

    Hedge Needs - Which Model is Best to use?

    Any suggestion?:)
  8. quotes

    Hedge Needs - Which Model is Best to use?

    I know the real stock price distribution has thick tails, so traditional BS method may encounter unexpected loss and may cost a lot. I want to hedge an option as smooth and cheap as possible. After all, if I underwrite an option, my profit is premium revenue minus hedging cost. If I have to...
  9. quotes

    Hedge Needs - Which Model is Best to use?

    However someone told me that SV model is not complete, so forget about it and just stick to BS.
  10. quotes

    Hedge Needs - Which Model is Best to use?

    I have heard the rumor that option shall be hedged according to recent volatility. So I guess a SV model outperforms a BS?
  11. quotes

    Hedge Needs - Which Model is Best to use?

    I am in a very immature market where even vanilla options are in scarce. To simplify the question, just hedge an European Call on a stock, which is the best?
  12. quotes

    Hedge Needs - Which Model is Best to use?

    So basically I can only use Black-Scholes or CEV to hedge them?
  13. quotes

    ito's lemma help

    Just suppose you have a time grid: t1-t0, t2-t1, t3-t2, ..., tn-tn-1 (tn=T) you want to generate a random motion W on it: W1-0, W2-W1, W3-W2, ..., Wn-Wn-1 (Wn=W) and you want the incremental W's to have the same independent distribution with expectation 0 and variance s*s So you get the total...
  14. quotes

    Quantile on normal and log-normal

    I guess you want to generate a random variable on normal or log-normal distribution through a simple random variable on uniform distribution. Let us just think it this way, you line up all your m classmates according to their height, from shortest to tallest. And then you get a quantile...
  15. quotes

    Question on an exercice of Joshi's Book

    If you are reading Concepts and Practice of Mathematical Finance, reread 6.108 & 6.109 on page 169
  16. quotes

    Hedge Needs - Which Model is Best to use?

    So do you know which model is best for hedging purpose?
  17. quotes

    Hedge Needs - Which Model is Best to use?

    Suppose you need to hedge an exotic option without any frequently traded vanilla option as means, and all you have is a money account and stock, then which model would you choose - simple Black-Scholes, CEV modification, Hull White or Heston Stochastic Volatility type, or Jump Diffusion? I came...
  18. quotes

    Any easy book on Heston Stochastic Volatility Pricing Model?

    Most textbooks stop at Geometric Brownian Motion framework. The advanced books are hard to understand. Can anyone tell me an easy introduction to Heston Model?
  19. quotes

    Question on an exercice of Joshi's Book

    Don't be too pushy on yourself, just relax.
  20. quotes

    Student-t Innovation Problems - GARCH(1,1)

    Could you tell us which book you quoted?
  21. quotes

    Risk Neutral Pricing = Martingale Pricing?

    Thanks for the recommendation. I will list Kerry Back's book as the next book to read after Shreve's.
  22. quotes

    Risk Neutral Pricing = Martingale Pricing?

    2.9 Numeraires and Probabilities?
  23. quotes

    Question on an exercice of Joshi's Book

    He said he used the stock measure. I guess B/S is a martingale instead?
  24. quotes

    Risk Neutral Pricing = Martingale Pricing?

    Thanks for your answer. Would you be more specific on the Margrabe's formula? Any paper or textbook? I think I have found the same conclusion that two risky assets can price an option on their exchange rate.
  25. quotes

    Risk Neutral Pricing = Martingale Pricing?

    Yes, that is what I mean - money market numeraire is not the only and essential option to martingale pricing. But I don't know why there is a need to show the uniqueness of a martingale measure of a given numeraire? Or like moretodo just said, there must be a riskless money market numeraire to...
  26. quotes

    Risk Neutral Pricing = Martingale Pricing?

    In Shreve's book, we see the discounted stock price can be changed driftless in some equivalent measure. And then by the Martingale Representation theorem, we can discount the expectation of the derivative values at maturity to price the derivative. However, there are other chances of...
  27. quotes

    Equivalent Martingale Measure and Market Completeness

    Well I guess I have not made the question clear. The traditional argument equates a risk-neutral measure to an equivalent martingale measure (EMM). But I doubt if a debt or bond asset is unnecessary in construction of equivalent martingale measure. Traditional arguments require at least one...
  28. quotes

    Equivalent Martingale Measure and Market Completeness

    Hi guys, I recently read about numeraire changing in Martingale Pricing technique. I heard the "Equivalent Martingale Martingale" dresses this issue and set a standard on whether there is a no-arbitrage price as the probabilistic expectation, called "Market Completeness". So do you have any...
  29. quotes

    Question on random number generator

    Maybe you are a A student in pure mathematics, but this post has nothing to do with answering the question. pruse has given an excellent answer by pure probability theory, and we all know that. Maybe the way he writes was not so polite, but keep attacking him only tells everyone your envy. Stop...
  30. quotes

    Accrued Interest & Dirty Price Calculation in Bond Pricing

    That is because bond traders quote their prices by accrued interest+clean price. The calculation of accrued interest helps traders quickly filter out the effect of different interest payment days and compare clean prices between bonds. Of course the standard way should be comparing yield to...
  31. quotes

    SDE and martingale

    I guess the reason why the problem is defined by martingale term instead of simply asking for a solution to an equation is that you can simplify the problem using Ito's lemma - like the way you posted in the end.
  32. quotes

    What is the proof for S * exp(-(d1)^2/2) = K * exp(-r(T-t)) * exp(-(d2)^2/2) ?

    I remember there is a proof in John Hull's book.
  33. quotes

    Baxter and Rennie - Previsible Process

    Previsible process means a random process whose state is determined before another process shows up the result i.e. We can buy the stock before it goes up or down, but we cannot go back to past to buy a stock that goes up today. The event of buying a stock relative to the price change is a...
  34. quotes

    Algo based on closing data

    MACD
  35. quotes

    Examine whether the log return follows a Brownian Motion

    If instead of a Bell curve you get the distribution a fat tail distribution, can we conclude it is a summation of normal distributions with different standard deviation? Consider the density p(X)=p(A)/2+p(B)/2 where p(A) = erf(s1) and p(B)=erf(s2) and you can get a mixture of them. Suppose...
  36. quotes

    Examine whether the log return follows a Brownian Motion

    I think of an idea to examine whether the underlying price movement follows a GBM. In a standard GBM We have log return like this Ln(Sj/Si) = (a-ss/2)(j-i)+ s(Wj-Wi) & E[(Ln(Sj/Si))^2] = ((a-ss/2)(j-i))^2 +ss(j-i) If we separate a time series of quotes of duration T into equal time...
  37. quotes

    Out of Money Lookback S(T) - 1.1Min(S(t), 0<t<T) ?

    Thank you for the reply, FKaria. The main reason for the volatility smile, so far as I understand, is that the distribution of the rate of return is not Normal. The heavy tail property of the real distribution in contrast to the theoretical Normal distribution, shows a lower normal standard...
  38. quotes

    Out of Money Lookback S(T) - 1.1Min(S(t), 0<t<T) ?

    Brilliant! The most traditional way- synthetic option!
  39. quotes

    Out of Money Lookback S(T) - 1.1Min(S(t), 0<t<T) ?

    I am so glad that finally someone replied my post. Thank you FKaria. I have found that Marc Yor and Geman Yor's book Mathematical Methods in Financial Market has a tedious proof. The reason why I need an analytic solution is I need to delta hedge and create the derivative. I don't know why a...
  40. quotes

    Out of Money Lookback S(T) - 1.1Min(S(t), 0<t<T) ?

    Hi All. There is formula ready for the lookback call option whose payoff at the maturity is S(T) - Min(S(t), 0<t<T) where S(T) is the terminal underlying price, and S(t) is the underlying price at time t, then the second term means the minimum of underlying price along the duration of the...
  41. quotes

    Difference between Heston model and "Schöbel & Zhu" stochastic volatility model

    How about using B-S framework directly to dynamically hedge an option? Is the tracking error too large to satisfy investors? Can Heston Model reduce the tracking error by a great deal?
  42. quotes

    Please help- Option pricing

    Answer to question 1: 0 ~ K2-K1 K2-K1 is the maximum loss at the maturity after shorting the C(K1) and longing the C(K2), which gains C(K1)-C(K2) to set up spontaneously. If C(K1)-C(K2)>K2-K1, setting up the portfolio will give you 0 chance of loss and some chance of winning. Could you...
  43. quotes

    Put-Call Symmetry by Peter Carr

    could you be more specific? P.S. It seems flawed with the quadratic variation drift 1/St=1/So exp{-(r-ss/2)t - sWt} =1/So exp{-r+sst/2 +sBt} Note +sst/2 here who contaminates a Geometric Brownian Motion formula
  44. quotes

    Put-Call Symmetry by Peter Carr

    The argument is really intuitive. If you get the right to buy 1 Euro by only K dollars, it is equivalent to K times the right to sell 1 dollar for 1/K euro. Thus their current value shall be the same Call(So, K) USD = K Put (1/So, 1/K) EUR = KSo Put(1/So, 1/K) USD Call(So, K)= KSo Put(1/So...
  45. quotes

    Put-Call Symmetry by Peter Carr

    Hello everyone, I heard a formula like C(S,K)=P(K,S) proved by Peter Carr. Its simple proof is on foreign exchange market where One Call on Euro denominated by Dollar is somehow equivalent to K Puts on Dollar denominated by Euro, considering the exchange effect, Co(S0,K)=KSo Po(1/So,1/K)...
  46. quotes

    Structuring : How would you replicate this Bond ?

    You said "if" in setting the future rates. How about "elseif"? If the spot rate set in future is only determined by the spot market rate then, you can replicate the rates by swap or whatever. For you are just hedging the future rate, by forward contract on future rates. However, if the spot...
  47. quotes

    Theoretical knowledge on Derivative

    Salih's book is a fine introduction. Its math is simpler than Shreve's. Besides, it proves maths problem friendly for beginners.
  48. quotes

    Pricing forwards paid in different currency

    Peter Carr's Symmetry
  49. quotes

    Alternative way to Solve Barrier Ending Density-Convolution?

    The reflection principle is a fine tool to solve barrier ending density as The distribution for a simple Brownian Motion ending value WT given a single barrier b was hit during (0,T] is N(x-b,sqrt(T)) I doubt if there are two other ways to solve this problem: reach (b,b+db) at some time t...
  50. quotes

    Stop Loss Strategy Does Not Make Money

    In martingale assumption, a stopped martingale is still a martingale. So if you stop gambling at a certain loss level. After many times of gambling, your expected profit or loss is still 0, fortunately, in a fair casino. So why do they set stop-loss strategy as an essential standard for...
  51. quotes

    Chaos Theory and Financial Markets

    Technical Analysis Regression Data Mining Chaos Discovery in ascending order of complexity
  52. quotes

    Hitting Time on a double barrier

    Here is Milo's solution: https://www.quantnet.com/forum/threads/double-barrier-ctd.8225/
  53. quotes

    First Passage Time of a Brownian Motion plus drift

    And then the four becomes two since the second and fourth term cancels out in the sum.
  54. quotes

    First Passage Time of a Brownian Motion plus drift

    \(N'(x)=\frac{e^{-x^2/2}}{\sqrt{2\pi}}\) \(e^{2\alpha m} N'\large(\frac{-m-\alpha T}{\sqrt T}\right)=\frac{1}{\sqrt{2\pi}}exp\large(2\alpha m-\frac{m^2+\alpha^2 T^2+2\alpha mT}{2T} \right)= N'\large(\frac{m-\alpha T}{\sqrt T}\right)\)
  55. quotes

    Double barrier, ctd...

    Good luck with your job hunt then. I will finish the drifted Brownian motion hitting one barrier post.
  56. quotes

    How to price an option with underlying mean-reverting?

    I felt unreasonable to use Girsanov to undrift a mean-reverting asset price. Suppose you have a GBM asset and a mean-reverting asset with the same volatility. Do the same option with these two assets as underlying share the same price? Why & Why not?
  57. quotes

    Double barrier, ctd...

    Good post, Milo. I am surprised by your persistence.
  58. quotes

    Merton's no early exercise theorem

    For European Options Call and Put, we have this equation: C-P=S-K/exp(r(T-t)) Thus C-P>S-K C>S-K Since the European Call C has value greater than its intrinsic value S-K, the more valuable American Call is larger than S-K as well. Thus you can always sell an American Call on the market at a...
  59. quotes

    Is it ever possible to dynamically hedge an option?

    I mean, there is an example in John Hull's book on dynamic hedging. The historical volatility is plugged in, and a replicating portfolio is constructed right from Black-Scholes. There is cumulative error during a period. However, is it practical to hedge an option on some stock in this way? Or...
  60. quotes

    Variance Gamma Model?

    Hi Moderator, help me move this post to "recommended reading", thanks.
  61. quotes

    call option sensitivity

    (c2-c1)/(s2-s1)=Delta So you know...
  62. quotes

    Variance Gamma Model?

    Does anyone know about a book introducing Variance Gamma Model from scratch? Thanks for any recommendation. :)
  63. quotes

    Critique my choice of courses

    It is hard to tell, Zubertrank. The courses have prerequisite conditions. For example, you cannot study 272C without studying 272A and 272B first, which means you have to learn 3 PDE classes altogether.
  64. quotes

    First Passage Time of a Brownian Motion plus drift

    \[e^{2\alpha m}N'(d2)=e^{-\frac{-4(m)(\alpha T)}{2T}}N'(d2)=N'(d1)\] - completion of squares It is the same way that Shreve used to simplify his complex intgrals. ;)
  65. quotes

    Critique my choice of courses

    Simply put, To come up with an option valuation, a quant either computes stochastic probability model or partial differential equation model, but may use Fourier transform method for more complex calculation. Stochastic Calculus tells you why and when to use the two and is the first class you...
  66. quotes

    Is quant finance back office work?

    Yes it is true.
  67. quotes

    Help!! Stuck with my Career

    I guess you are not a US citizen, Pradhu. It is very bad now in quant hiring in US. The best choice for you is learning by yourself. And then it is up to you to go abroad or land a local quant job. I could recommend the books I have used for you. They are not that hard if you learn step by step.
  68. quotes

    Is an PhD in engineering physics too "applied" for a quant job?

    Nano, it depends on your knowledge. Have you learned Stochastic Process? Have you learned Fourier Transform? How well can you solve a Partial Differetial Equation? How much have you mastered Statistics? If you pass the four questions, the only block between you and a quant job is Shreve's book.
  69. quotes

    Help!! Stuck with my Career

    Quant is not suggested regarding your corporate finance background. How about Venture Capitalist? Stock Analyst? Passion for Numbers \= Passion for Formulas. You need to be very easy with Calculus and Statistics (including Econometrics) to be a successful quant.
  70. quotes

    Securitization Structuring Issues - Pls Help

    Do you know binomial models, Anna?
  71. quotes

    Delta=N(d1) ???

    Oh thank you Bucks, I just remembered my professor did mention this problem and I found in John Hull 6e Homework 13.17 on this matter. Yes they cancel out.
  72. quotes

    Delta=N(d1) ???

    If the derivatives of N(d1) or N(d2) are not in consideration, the partial derivative on the latter, negation of a share digital option is zero as well, which contradicts reality.
  73. quotes

    Delta=N(d1) ???

    I found the definition of delta with respect to an European option problematic: (\frac{\partial C}{\partial S_t}=\frac{\partial}{\partial S_t}(S_t N(d1)-Ke^{-r(T-t)}N(d2))=N(d1)) while d1 and d2 are actually functions of S. Shall we count in the derivatives of N(d1) and N(d2) ? Or the...
  74. quotes

    Online math courses for MFE applicants

    They'd better say Shreve and Glasserman so that they got tuition without teaching.
  75. quotes

    Time for a Change in Structure of MFE Programs

    There are two different expectations on an financial engineer: Price and hedge derivatives as accurate as possible; Make correct bets on the market through statistics and mathematics. The first one is difficult yet accessible to fulfill, but the second one is almost impossible to find...
  76. quotes

    Critique my choice of courses

    On numerical methods, you only need an R and some Monte-Carlo books to develop your own algorithm. You can self-study numerical methods on probabilistic approach.
  77. quotes

    Critique my choice of courses

    If you want to learn derivative pricing well, here are road map to its knowledge needed Mathematical Finance or Stochastic Calculus - The first and foremost thing you need to understand, and any other knowledge serves it. And from here you can dig into 2 areas: Stochastic Process - the...
  78. quotes

    Online Library is DOWN

    I really thank library.nu for their pirated books. Choosing a good book in a particular field is almost impossible without viewing a large amount of books in that field first. Only after reading many books can I buy one truly excellent one.
  79. quotes

    Online Library is DOWN

    The world largest scientific e-book site library.nu is closed today, warning that: Library.nu is offline today (joining large sites such as Google and Wikipedia), because the US Senate is considering legislation that would certainly kill us (and most of the internet) forever. The legislation...
  80. quotes

    First Passage Time of a Brownian Motion plus drift

    Mark Joshi only gaves 2 pages explaining reflection principle in his book Concepts and Practice of Mathematical Finance The problem with most stochastic finance books is that they only briefly discuss the barrier problem from one or two aspects, thus any book is incomplete treating the...
  81. quotes

    First Passage Time of a Brownian Motion plus drift

    It is just your formula given in post 6 simplified and multiplied by (-1) Try it.
  82. quotes

    First Passage Time of a Brownian Motion plus drift

    I understand what went wrong regarding negative sign These two are not equal but complimentary: \(P\{\tau _m \le T\}+P\{M(T)<m\}=1\)
  83. quotes

    asset pricing research

    Bessel Process and Variance-Gamma ? There are alternative models than Black-Scholes, and it is challenging even today to construct and to calibrate them in financial markets
  84. quotes

    First Passage Time of a Brownian Motion plus drift

    See, if you differentiate P{M(T)<=m} with respect to T, you just get negative values. To simplify, just make a=0 the driftless case: \(-\frac{m}{2\sqrt{T^3}}N^{'}(m/\sqrt{T})-\frac{m}{2\sqrt{T^3}}N'(-m/\sqrt{T})\)...
  85. quotes

    Pls someone can help me with equiv MARTINGALES! :(

    completely lost in your symbols. you can use Latex with (tex) (/tex) but [] instead of () However you need to define each variable you use.
  86. quotes

    Duration

    This article explains the link between DV01 and Duration. You may have already figured it out before reading it. http://www.closemountain.com/papers/risktransform1.pdf
  87. quotes

    Duration

    No it is not change in value expressed in dollars.
  88. quotes

    Forward Curve

    It is impossible to determine a commodity forward price function with respect to time, spot price and cost of carry. The convenience yield is determined by the difference between real forward spot spread and cost of carry. The former is suspect to volatile supply and demand.
  89. quotes

    Duration

    (MD=\frac{\Delta P/P}{\Delta r}) Check the detailed formula with this. If it does not fit, it is wrong.
  90. quotes

    Constraint on Girsanov Transformation

    No. Shreve's proof is only a sketch. I found the drifted Brownian Motion must be at least Markov to determine the time differential of Radon-Nikodym derivative before multiplying them up.
  91. quotes

    Constraint on Girsanov Transformation

    On page 212, he indeed states (\Theta (u) ) needs to be an adapted process, and the convergence condition comes from 4.3.1, where Ito integral is defined. He further showed an example in 4.3.8 that the integrand in an Ito integral can be stochastic (in fact can jump) but is still a martingale...
  92. quotes

    Constraint on Girsanov Transformation

    Sorry I misinterpret the definition of "adapted" as "previsible". What I meant in post 5 is that if drift is "previsible", then it can be treated as constant in discrete time intervals like the weights in a self-financing portfolio. Therefore my challenge on the theorem still stands. It is...
  93. quotes

    Free Online Quantitative Finance Textbook

    These lecture notes are also available http://galton.uchicago.edu/~lalley/Courses/390/
  94. quotes

    Constraint on Girsanov Transformation

    "adapted process" might mean that for any given small time interval, we already know the drift before hand, therefore drift is held constant in that interval and not stochastic compared to the volatile part of Brownian Motion. The Girsanov's Transformation originally involves only one Brownian...
  95. quotes

    Constraint on Girsanov Transformation

    To simplify, just the drift of the diffusion.
  96. quotes

    Constraint on Girsanov Transformation

    If the drift of a Brownian motion is constant, Radon-Nikodym derivative could be applied to Girsanov transform the drift to zero, or from zero to a constant. This is no doubt. However, I doubt if it can also be applied to a stochastic drift, say, a mean-reverting stochastic drift. Just...
  97. quotes

    Alternative models than Black-Scholes?

    I got hammered in a seminar last evening. The Morgan-Stanley Doctor said people no longer use simple Black-Scholes setting in Wall Street. They add in Heston Volatility Model to capture the irregular up and downs of price movement. This is a real blow since the whole book of Shreve turns...
  98. quotes

    Free Online Quantitative Finance Textbook

    http://www.opentradingsystem.com/quantNotes/main.html explicit illustration, large coverage, but poor background theme.
  99. quotes

    Fourier Transform in Option Pricing?

    It is very odd that Steven Shreve left some Fourier Transform on hitting time proof in his book. And it seems fourier method might be another option in option pricing rather than PDE and martingale approach? Anyone who knows about it?
  100. quotes

    First Passage Time of a Brownian Motion plus drift

    If we differentiate the Probability of event {M(T)<=m, X(T+r)>m}, or that X(T) breaches the upper barrier m in time interval (T,T+r] , with respect to time increment r, we get the hitting time distribution of X(T): \[\frac{ -\partial P}{\partial T}=\frac{m}{T\sqrt{2\pi T}}e^{-\frac{(m-aT)^2}{2T}}\]
  101. quotes

    Basic question

    You can change sample time so long as your option price and stock price are observed at the same time. So it is okay to use Monday opening for both prices.
  102. quotes

    Basic question

    the option value is replicated by a self-financing portfolio, which is set up prior to price changes and can still hedge small random shift of the underlying price in a short period. Both the value and the component of the portfolio is "previsible" about the underlying price change. Therefore...
  103. quotes

    Stochastic process in finance

    It depends on how much you want to know. Search "Brownian Motion" in wikepedia and you get the first impression.
  104. quotes

    First Passage Time of a Brownian Motion plus drift

    The event {M(T+h)<=m} contains the event {M(T)<=m} where h>0 So {M(T)<=m}-{M(T+h)<=m}={M(T)<=m, X(T+r)>m} where 0<r<=m That is where I got the clue.
  105. quotes

    First Passage Time of a Brownian Motion plus drift

    Sorry for my previous mistake, X(T) shall be M(T) in the equations. \(P \{M(T)\leq m\} = N(\frac{m-aT}{\sqrt{T}})-e^{2am}N(\frac{-m-aT}{\sqrt{T}}),m>0\) \(\frac{\partial}{\partial T}P\{M(T)\leq m\}\)
  106. quotes

    Screwed up my life

    Take a GRE exam and prove your IQ. Some graduate schools value GRE more than education.
  107. quotes

    First Passage Time of a Brownian Motion plus drift

    Shreve 7.2.2 Under Probability P, W(T) is a standard Brownian Motion while X(T)=W(T)+aT is a Brownian Motion plus drift. M(T)=Max{X(s); 0<s<T} \(P \{M(T)\leq m\} = N(\frac{m-aT}{\sqrt{T}})-e^{2am}N(\frac{-m-aT}{\sqrt{T}}),m>0\) Can we differentiate the above to get first passage time...
  108. quotes

    Realized Volatility Calculation

    In finance, we don't care about how the drift udt might vary over time, so it is good to have a volatility estimate independent of time drift estimate. True, you can use a R=udt+sdW to estimate s, but at the same time you assume u holds constant among your sample and estimate of s is based on...
  109. quotes

    Hitting Time on a double barrier

    Thank you. Thanks for your notation, but I have seen the formula in infinite sum.
  110. quotes

    Hitting Time on a double barrier

    O stands for the ball running. initial spaces are cut off so you may not see the trajectory of O clearly, but the O does a random walk verticly and a straight line movement horizontally.
  111. quotes

    Hitting Time on a double barrier

    Okay, suppose you are observing a ball running along the time horizon before a right bound T. However it must stays between the line y=a and y=b, once it touches either line, it is finished and no longer runs. _________y=b__________ O O 0- - - - O- - - - - - - >- - - - - --...
  112. quotes

    Unfinished Gambler's Ruin

    This is for single barrier. You need to consider the case that the Wt stopping at a before b, thus reducing the chance stopping at b, I guess.
  113. quotes

    Hitting Time on a double barrier

    No, a<W(T)<b and W(t) before W(T) in its path cannot hit either a or b. T is forced stopping time. You can interpret it as Game Over Time - forget about Wt continuing or stopping at barrier a or b, now at time T it stops at whichever value.
  114. quotes

    Hitting Time on a double barrier

    Let me clarify the symbols a little bit. The Process(t,W(t)) stops at (Ta, a) (Tb, b) or (T,W(T)) for the first two occasions, W determines the stop, and for the last, t determines the stop The question is: 1) Prob(0=<Ta<u<=T) 2) Prob(0=<Tb<u<=T) 3) Prob( a=<W(T)<=u, u∈[a,b]) Of...
  115. quotes

    Hitting Time on a double barrier

    Wt stops when it hits a<0 or b>0 Is there a formula to determin P(Wt=a, t<T) and P(Wt=b, t<T)? Any help would be appreciated
  116. quotes

    List of sample questions for Quant Interviews

    Unfinished Gambler's Ruin Can you answer the question in this post?
  117. quotes

    More mathematics than Steven Shreve's book

    Currently my research focuses on double barriers, a rare topic in textbooks.
  118. quotes

    More mathematics than Steven Shreve's book

    Thank you. I have downloaded her lecture notes.
  119. quotes

    Unfinished Gambler's Ruin

    Suppose a Standard Brownian Motion Wt without drift. Wt stops when any of the three circumstances below occurs: Wt=b>0 Wt=a<0 t=T Traditional Gambler's Ruin problem focuses only on the T=inf case. However, I want to know P(W ends up at b) and P(W ends up at a) and of course P(W ends at T)...
  120. quotes

    List of sample questions for Quant Interviews

    How about the process with finite time allowed? To preserve a martingale P(ending in upper boundary)+P(ending positive in the end but below upper boundary)=0.5 Am I correct?
  121. quotes

    A Stopped Martingale is still a Martingale?

    For example, an up-and-out call option with Barrier J and Strike K<J. The stock price stops at barrier J at time t <=T. In a risk-neutral measure, J(s=inf{t St=J})*exp(-rs) & S(T)*exp(-rT) is a martingale, correct? Then we have a stop boundary for the martingale S(t)*exp(-rt) a near flat curve...
  122. quotes

    More mathematics than Steven Shreve's book

    I guess the deeper mathematics than Shreve involve mainly two areas: One is deeper Calculus like Protter One is deeper probability with martingales like Williams And do I need to understand both?
  123. quotes

    Boston MSMFT Boston University: Mathematical Finance Interview

    Say you like party in Boston :D
  124. quotes

    More mathematics than Steven Shreve's book

    The reason is that Shreve's book does not provide sufficient knowledge for me to read papers.
  125. quotes

    More mathematics than Steven Shreve's book

    I lack measure and probability background. The only thing I know about is statistics at undergraduate level. I do have Models for Probability and Statistical Inference by Stapleton - have not covered convergence part However its focus is on Classical probability instead of stochastic probability...
  126. quotes

    More mathematics than Steven Shreve's book

    It seems very short. Haven't tried yet. Currently I have downloaded these books: Arbitrage Theory in Continuous Time by Bjork Mathematics of Financial Market by Elliott and Kopp _They are at the same level as Shreve Continuous Martingales with Brownian Motion by Marc Yor - difficult...
  127. quotes

    More mathematics than Steven Shreve's book

    Hello Everyone, I am looking for some books on the foundations of Stochastic Calculus with more mathematics. Because I feel even Shreve's book isn't clear enough on some topics. What makes it worse is that some French book like Mathematical Methods for Financial Markets seems so difficult...
  128. quotes

    New to the game

    I hate GPA Different Schools have different GPA standard. Plus, teammates can affect your GPA too.
  129. quotes

    Terminal Vs. Immediate Payoff for a Barrier

    No it does not seem correct. I have to know precisely when the barrier is hit and come up with the present value.
  130. quotes

    Terminal Vs. Immediate Payoff for a Barrier

    Thank you for clarifying the post. Yes you got what I mean. My question is : is there still a probability approach to price the Instant one touch? I came up with something like forward as the underlying, but the slope barrier for the forward. Obviously, it complicates the path but simplifies...
  131. quotes

    Stochastic Differential Equation and a Martingale

    you mean R(t)=W(T)-W(t) ???
  132. quotes

    A Stopped Martingale is still a Martingale?

    The stock price S does not stop at the barrier, but does the replication portfolio of a barrier option. Shreve illustrate that the barrier option stopped is still a martingale, but I still have not understood that.
  133. quotes

    A Stopped Martingale is still a Martingale?

    So you want to say that a Freezed martingale is still a martingale? If (e^{-rt}S_{t\wedge T_B}) is a martingale, (e^{-rT}S_{t\wedge T_B}) is not.
  134. quotes

    A Stopped Martingale is still a Martingale?

    Textbooks proved this. Wt∧Ta, where Ta = inf{t: Wt=a}, is also a martingale when Wt is a martingale. Does it prove anything? To price barriers? Any explanation? I am totally confused on its usage to price barrier options. Thanks in advance.
  135. quotes

    Quadratic Variation to estimate Volatility

    Shreve uses (log(St+1)-Log(St))^2 to estimate the volatility.
  136. quotes

    Terminal Vs. Immediate Payoff for a Barrier

    Consider two digital barrier options: One gives off 1 at expiry so long as the underlying spot reaches some level before expiry The other gives 1 immediately when the underlying spot hits that level Of course these two options should have separate value. I assume the first have a textbook...
  137. quotes

    I want to publish a small essay, where to?

    Hi Tobi, I have already graduated from MSF in another country. I don't know if I could contact my professor with a discussion. Besides, I don't want to tell anyone other than the committee of a journal about my finding. This is the major issue between me and my professor.
  138. quotes

    Master reading list for Quants, MFE (Financial Engineering) students

    If you mean stochastic probability, Shreve's book can do the job.
  139. quotes

    Quadratic Variation to estimate Volatility

    since dSdS=σσSSdt Isnt't more straight forward to add up (St+1-St)^2 to estimate the volatility for a Geometric Brownian Motion?
  140. quotes

    Aerospace Engineer To Quantitative Analyst?

    Fluid dynamics is a much more complex field than pricing derivatives. I feel like you are dropping a finance career for an accounting one. Derivative pricing (quantitative finance) is really not that hot given your math background. If you really need to make a fortune through financial market...
  141. quotes

    Best instrument/method for speculation?

    Forward you need 0 initial investment.
  142. quotes

    Table of known SDE solutions

    There is no table like that. Aside from solution to Geometric Brownian Motion, there are solutions to several mean-reverting SDEs. And those are all we have.
  143. quotes

    When to use Monte-Carlo?

    In terms of European Option, worse than an expectation numerical integral. In terms of Path-dependent exotic, looks good but with too little sample problem. In terms of American Option, already other methods. When is the application of MC better than other approaches?
  144. quotes

    I want to publish a small essay, where to?

    My approach to prove existing theorem looks simple but is relatively new. It contains one page or two, and few references. Do you know some journals that accept such paper?
  145. quotes

    Black-Scholes PDE with boundary conditions

    Another option pays the same but lose effect when the underlying hits another level.
  146. quotes

    Black-Scholes PDE with boundary conditions

    Well could you tell me if this is a time dependent boundary or not? An option pays 1 dollar immediately when the underlying hit a predetermined level before expiry.
  147. quotes

    Paradox with Ito Caculus

    \[d\frac{S}{S}=\frac{dS}{S}-\frac{SdS}{S^2}-\frac{dS^2}{S^2}+\frac{SdS^2}{S^3}=0\]
  148. quotes

    Paradox with Ito Caculus

    \[d\frac{X}{Y}=\frac{d X}{Y}-\frac{Xd Y}{Y^2}-\frac{d X d Y}{Y^2}+\frac{X d Y d Y}{Y^3}\]
  149. quotes

    convert discount rate to continously compounded yield to maturity

    Suppose you have a bill with discount rate 4% and 1 month to maturity. The actual discount factor is 4%/12. So the bond is worth 1-4%/12 =PV Another point of view on this bond is (100/PV)=(1+YTM)^(1/12) Then you may solve the YTM. I guess the formula is Not correct.
  150. quotes

    Black-Scholes PDE with boundary conditions

    My problem is a double barrier option between two slope lines (instead of known interval X in (a,b) ) Thank you.
  151. quotes

    Two definitions of utility functions and coefficients of risk aversion?

    You have to ask your teacher which Utility function and which distribution he assumes in the second problem.
  152. quotes

    Paradox with Ito Caculus

    Thank you.(y) How did you input formula BTW?
  153. quotes

    Paradox with Ito Caculus

    Hi everyone, I have a peculiar problem here: d(S/S) = d(1) =0 d(S/S) = dS /S+S d(1/S) <product rule> d(1/S) = -dS/ S^2 + (dS)^2/S^3 d(S/S) = dS/S - dS/S + (dS)^2/S^2 =(dS/S)^2 0 =? (dS/S)^2
  154. quotes

    Stochastic Calculus

    Alison Etheridge's A Course in Financial Calculus is a strong recommend It has explanations, and very rigorous proofs, also deep concepts, yet unsolvable exercises, plus many typos. If you are bored by Shreve, try Alison. It will give you some challenge and thinking. If you feel it is still...
  155. quotes

    Double Barrier Options (Double Knock-outs)

    Thank you guys for your kindly advice. Double Barrier seems to be infinitely harder than One Barrier. The transition density is an infinite series because of infinite reflections between the upper and lower boundary. It was not until late 1990's until mathematicians developed fast series...
  156. quotes

    What Should I Aim For? Math undergrad at Cambridge

    Considering your background, I would really suggest you drop the idea of being a derivative quant. There are too many quants and MFEs nowadays to price financial derivatives. Working in the financial business does not mean you need to know how to price derivatives, which is a small fraction of...
  157. quotes

    Black-Scholes PDE with boundary conditions

    A typical European option pricing via Black-Scholes approach is to solve a Black-Scholes PDE with terminal option payoff f(T,x) Simply put, a Black Sholes PDE involving the first derivative of option value on t and on x (the value of underlying security) and the second derivative on x, with a...
  158. quotes

    Rational for Continuous Risk-Neutral Pricing

    Thank you DStahl. I checked some textbooks - Feyman Kac Theorem guarantees martingale pricing would work for any European Options whose boundary condtion is at maturity. However, the applicability of the martingale approach to path-dependent options remain plausible.
  159. quotes

    Double Barrier Options (Double Knock-outs)

    do you mean use the implied volatility of a call to monte-carlo the double barrier?
  160. quotes

    Quant - Statistics/Econometrics vs Stochastics Calculus

    Yes you got it. Derivative pricing techniques work only well in financial derivatives. Any other field, econometric.
  161. quotes

    Recommended books to understand Brownian motion, ornstein-uhlenbeck process, arbitrage, and market

    These books are on my shelf. How about Robert Elliot & Ekkehard Kopp Mathematics of Financial Market and Tomas Bjork Arbitrage Theory in Continuous Time?
  162. quotes

    Which PDE book to read?

    Partial Differential Equations are generally very difficult to solve. It is not like the integration where you just need to remember under 20 common integrals in order to solve most problems analytically. Sometimes a difficult boundary condition (similar to upper and lower limit of a integral)...
  163. quotes

    Econometrics books for practitioners

    Russell Davidson
  164. quotes

    Freely Available Software for Linear Algebra

    There is a freeware similar to matlab, but I have forgot its name, just remembering it starts with "O".
  165. quotes

    An Ethical Question !

    Yes, people do need exotics to gamble in the market. e.g. Some people give up forecasting the price of a stock, but he/she is confident to gamble its volatility. And a convertible might be used to place the bet. A convertible, widely recognized as a special kind of debt, is in fact a very...
  166. quotes

    Rational for Continuous Risk-Neutral Pricing

    Hi everyone, I have a serious doubt: What is the rational for risk-neutral pricing in continuous Geometric Brownian Motion? I know the techniques -Girsanov transformation and discounting expectation But I don't know why Why this can price an option? Why this can price an European...
  167. quotes

    An Ethical Question !

    fufil-satisfy or you could say deceitfully satisfy like no-risk supreme debts, here the "no-risk" is equivalent to "healthy"
  168. quotes

    An Ethical Question !

    Of course there are misuse on fixed-income derivatives. It is like healthy hamburger - unqualified products to fulfil unrealistic customer need
  169. quotes

    An Ethical Question !

    Financial Engineering adds marginal value on financial products - it flavours the underlying to varies taste for investors. metaphor: I don't want a stock, but I want an option derivative on that stock. <=> I don't want a plain ice-cream, but I want a chocolate flavoured ice-cream. You can...
  170. quotes

    Is yield to maturity for a 10-year Treasury security for a year or half a year?

    yield to maturity measures the IRR, internal rate of return, and it is the compounded interest rate. You should be able to use YTM to discount all the future cash flows of that bond to its dirty price today.
  171. quotes

    Double Barrier Options (Double Knock-outs)

    I need advice on pricing a double knock-out European option whose pay-off at the end is only allowed so long as the underlying has not breached an upper and a lower bound within the option life. e.g. A European Call with strike 20 dollars with both 25 dollar up-and-out and 15 dollar...
  172. quotes

    Path-Dependent Monte Carlo

    I bet Monte-Carlo has far little possible paths than a binomial tree. Say, 2^100 paths only need 100 time points in a tree. Monte-Carlo has a finer ending-time distribution, but too little paths have insufficient representation in a path dependent model. Therefore, I prefer binomial model to...
  173. quotes

    Greeks: barrier up-and-out

    If you have the analytic solution, I guess you could differentiate it with respect to S
  174. quotes

    Binomial Model - Plotting time evolution of Derivative

    If you mean you want to plot all the paths out, I would suggest you give up. Because there are 2^100 different paths within your 100 -step binomial tree. Simulating paths is a necessary procedure in Monte-Carlo simulation, which however produces far less possible paths than a large binomial...
  175. quotes

    Risk Neutral valuation

    You don't need to. But Geometric Brownian Motion is the most popular model to reflect stock price movement nowadays.
  176. quotes

    The Risk Neutral Measure

    You have post a serious but often neglected question. Not all distributions can be easily shifted to a risk neutral measure to price an option via martingale approach. It has to be transformed through Radon-Nykodym derivative. The book Brownian Motion Calculus may answer your question on...
  177. quotes

    Random Walk

    Because your steps are not dense enough. Besides, this multiplicative model has error simulating a Brownian motion, try additive model instead, which simulates log(S(t)) and you will never get a negative S(t).
  178. quotes

    Binomial Option Pricing

    Sure you can. But there are better ways to evaluate an European Option.
  179. quotes

    Suggestion on Brownian motion simulation

    Yeah, Brownian Bridge. Build a Brownian midpoint between the initial value and the ending ones, then build 1/4 points between the three. And the list goes on until you feel the path points are as many as you want.
  180. quotes

    jump model vs. BS model

    Well, some criticisers on jump-diffusion models simply don't calculate them at all. It is useless when I don't have it.
  181. quotes

    How to price American Options using Monte Carlo???

    I prefer excel to matlab to calculate an American option.
  182. quotes

    Master reading list for Quants, MFE (Financial Engineering) students

    A Course in Financial Calculus -the book that saved my education in quant
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