That’s true, in much the sense that doctors make money off people being sick. In times of high volatility, it’s HFTs that provide liquidity and keep spreads nar

That’s true, in much the sense that doctors make money off people being sick. In times of high volatility, it’s HFTs that provide liquidity and keep spreads narrower than they’d otherwise be. It is extremely illegal to purposefully make markets more volatile; good trading firms are not going to do that.