I'm no expert, but I think the AI's strategy works because people read news articles about stocks and then buy and sell in large numbers, causing a stock to tem

I'm no expert, but I think the AI's strategy works because people read news articles about stocks and then buy and sell in large numbers, causing a stock to temporarily be valued higher or lower than it "should" be. By taking out some of the profit of knee-jerk reactions to news, the AI encourages people to be more restrained in their reactions, to consider longer-term effects, which makes for a more stable market.