Quote from youngtrader:
That doesnt make any since with the cups. Why would you switch cups? Wouldn't that just be second guessing yourself? If you picked that cup in the first place and then you have the opportunity to switch how can you determine that you have better odds picking the other cup? Its a 50-50! That is probably the most retarded thing I have ever heard lol! Now im gonna be honest im a C student in math and absolutely hate it and find no use in calculus or algebra. Remember trading is a social science at best not a pure science like math, physics and such. So it will never be mastered by those nerds!
Look it's simple. When there are 3 cups, it's a 1/3 chance you are right and 2/3 that you are wrong. Once one cup is removed, it's now 50/50 but only so if you actually make the switch. Otherwise, you are really sticking to your old choice which is STILL 1/3 correct, 2/3 incorrect.
It makes more sense if you increase the numbers, like start with 10, pick one, then the host removes 5 wrong ones and asks you if you want to stick with your original choice.
It's a good question to ask and is somewhat applicable to trading. Often variables involved in decision making are affected in a similiar fashion, especially if you lean toward arbitrage, relative value & mean reversion strategies. It tests your ability to understand guesswork in trading, recognizing potentially wrong choice with new information, then making a better decision. Because each trade is essentially a guess based on the information you use at the time. Especially when it comes to the Quants, it's just repeated guesswork over and over based on a model.
Problem with quants is the lack of knowledge and experience of the key driving factors, greed & fear. That's no Monty Hall concept, it's psychology. For example, (and I think arrogance was a key flaw in this), when these quant progs started failing in August, someone at MS should have said "Gee, the rest of the big boys are running the same Quant crap and if we are puking, they must be too, so why not capitalize on that?" But I don't think those type of guys work there anymore.