I believe my question will look quite naive, sorry for that. Moreover, there are hundreds of posts like this "what are my odds to do 'phd in physics -> quant' transition", but each situation is different and as I understand, the situation in finances usually changes fast!

I am a theoretical physicist, finished my phd 3 years ago, had a practical postdoc in a national lab and now I work as a theoretical physicist in industry for 1 year. I am in my late twenties. My field is very practical (vs other branches of theoretical physics). Essentially, I solve ODEs and PDEs. Analyze analytically and solve numerically. I have broad experience writing and using different numerical methods: finite difference, finite volume, finite elements, spectral methods, spectral elements, etc. + different linear/nonlinear solvers, Krylov methods, multigrid, different iterative solvers, Newton methods, jacobian free methods etc. with different time marching strategies, i.e., explicit, implicit, symplectic, imex, etc. This is all in HPC settings, so I do it in parallel - MPI, openMP. I am not a mathematician who develops those methods (I did a bit), but I use them to solve my physics problems and I write code to use such methods. I do not blindly solve equations numerically, and I frequently do some analytical work as well, so I am proficient with math.

In terms of programming I think I am okayish. I mostly write C, C++, and julia. I can probably read another 10 languages including python. I played with lisp and haskell in the past. Without preparation, I probably can remember basic data structures and algorithms, like trees, stacks, pipes, quick sort, merge sort, state machine - that type of things. I know some OOP.

I will definitely need to refresh algorithms, some statistics, and brain teasers - this is just a crude overview of my background.

Main problem is that I do not know finances at all. I took some micro/macro economics classes in my undergrad, but I forgot all of it.

What am I looking for: I want an intellectually challenging job with lots of math and programming (I love programming and I want to become better in it). I do not care if the math I do describes physics or finances... Salary improvement is very desirable. This looks like a "quantitative researcher" position. I want to relocate to NY and I do not need a visa to work. I have other personal reasons which motivate me to change.

My question:

1) What are my odds to find a quantitative researcher position without internships or additional degrees? I am willing to spend time to prepare of course.

2) Does this timeline "3 months preparing + 3 months preparing and looking for a job" look too unreasonable?

3) What do you think is the starting salary I can hope for? What about a salary in 5 years?

4) How is the "finance sector" doing right now? what are the odds to just lose your job in ~1year. How difficult will it be to find a new job again?

5) There are lots of "quant" positions... what would be the most math heavy?

6) Anything crucial I should be aware of?

7) I know that this is a big shift, and I still evaluating if I should do it and I am learning about my options. So if you were/are in similar situation, can you please comment your thoughts and if you are happy with your decision.

8) Any other advice is very much appreciated!

Thank you very much!