Yes, I read it some time ago. But as disturbing as it was, at least the basic principle was comprehensible: arbitrage carried to ridiculous extremes. I don't know anything about the newer AI techniques that traders are using, but what worries me is the likelihood that the decision making is opaque, based on patterns that only a neural net can see. I'm not an economist, but I suspect that could cast doubt on the basic assumption of rationality in the market, without which there's no longer any theoretical reason to expect good outcomes globally. If the decision making cannot be codified in human form, it becomes more difficult to impose regulation to constrain the consequences. I should add that I don't know that any of this is actually happening--one would think that traders would be reluctant to "just let the computer decide"--but who knows? I do know of some AI managed funds, but I don't know whether there are enough of them to move markets or whether they have built-in limits on trade size or speed.