I've read elsewhere on here that the value of high-frequency trading is that it reduces transaction costs and increases liquidity in the market. I.e. it makes it easier for the humans to buy and sell at the prices they wish to buy and sell at.
Assuming that's true, the question then becomes what are the costs and externalities of HFT and, in balance, are we willing to make those trade-offs? I haven't seen anything addressing those issues yet, but I haven't been looking either.
HFTs tend to add liquidity when it's least valuable, and they tend to consume liquidity when it's most vital.
For example, an analysis of the 2010 flash crash shows it was worsened by HFTs fleeing their positions once volatility increased, which is the exact time that liquidity and market-making are most valuable.
If there is any social benefit to HFT it is utterly trivial.
Assuming that's true, the question then becomes what are the costs and externalities of HFT and, in balance, are we willing to make those trade-offs? I haven't seen anything addressing those issues yet, but I haven't been looking either.
HFT experts want to weigh in, pro/con/otherwise?