Sorry this may be a newbie question, but I'm not a quant or statician. I've read that you need to have an edge in the markets so over time you will end up on top, similar to how casinos end up winning over the long run. But I've also read that the trade you place now is independent of the past trades you have made. For example, let's take roulette. Since casinos have the edge, it's better to place the majority of your money on the first spin because the outcome is more random. Statistically speaking, the longer you play, the more you'll lose, correct? And every spin is independent of the one before regardless of it being a winner or loser. My newbie question is, how come you can't treat every spin you make like it was your first spin? Since its the spin is statistically independent of one another. I understand the concept of casinos having an edge a little, but this question has been bugging me. Thanks guys for all your help.