In this case, the system would be self adapting. After all, it just looks at a sliding window of what has been successful in the last X days and acts on that information. Something happens that is unexpected? Sure, efficiency drops for a little bit – and then the entire system moves on.

You mention the stock market, I'll counter with the weather. If you want a greater than 70% prediction rate, just assume that tomorrow will be within 4% to 5% similarity of today. Throw yesterday and, do a very basic trend analysis, and you can be over 80%. And that's with a very stupid algorithm.

I'm old-school when it comes to AI and markets. I firmly believe in "good enough" technology. It doesn't have to be perfect – it just has to be good enough. It doesn't have to be good enough all the time, it just has to be good enough for a good enough portion of the time.

You can get away with a lot of slop if that's your target space, and you can get to it very fast, and very cheap.