> And it is possible for someone to enter the market using a different algorithm. By the way, I think this often happens in the real world, where some person i

> And it is possible for someone to enter the market using a different algorithm. By the way, I think this often happens in the real world, where some person irrationally (from the economist's point of view) provides a valuable, yet underpriced (with respect to the real demand curve) service, because he is just being misinformed, idealistic or is interested in success for its own sake, not for the sake of money. Or it's just that the product is new and actual demand curve hasn't been established yet. Absurdly, this is then hailed as an example of market efficiency, while there is nothing rational in such behavior from the game theory perspective (unless you consider much wider frame of how human morality evolved etc.).