Quote from asap:
blackjack or any other game of that sort or trading is pretty much the same, as far as expectation is concerned, that is, negative expectation.
betting strategies don't alter the expectation of the game. the only way to make money in the long run, is by reverting the built in negative expectancy, which in blackjack is only possible, when counting cards is a viable option.
in trading, reverting negative expectation is hard but has been done many times through i.e. inside information, arbitrage, or systematic trading. again, betting strategies in trading don't alter the expectancy, but can change the smoothness of the equity curve.