I think you're coming in with an assumption that HFTs are generally correct in their valuations, and that they are chasing efficiency or proper valuations rather than short term gains.
Maybe those would be roughly analogous in a stable situation, but my read is that the big players in the markets today are chasing short term gains despite the signals. I'd point to the housing crisis as a recent example, the biggest banks and funds were massively over valuing real estate and real estate derivatives because they were blind to the actual risks and saw what appeared to be free money.
There are so many misconceptions about what HFTs do and if anything they seem worse here than average.
HFTs do not (for the most part) have any kind of “valuation” of stocks based on the fundamentals of companies. To a first approximation most HFT strategies are market making- they buy from people who want to sell at 9 and they sell to people who want to buy at 10 and every time they successfully do that round trip they make a dollar.
There’s more to it than that because of course there is. Markets are complicated and there are a lot of market participants trying to do lots of things. So sometimes they make use of their knowledge of market microstructure to try to detect and preempt big market moves (eg index rebalances, big portfolio unwind trades etc).
But don’t think HFTs have a perspective or care about the value of TSLA or whatever as a company. They basically want people to trade TSLA a lot so they make the vig every time they do. As some sibling has pointed out, they don’t want toxic/directional flow though, they want balanced flow because that means they keep making a clip whereas directional flow leaves them holding a lot of risk one way or the other because they are on the other side of those trades.
Maybe those would be roughly analogous in a stable situation, but my read is that the big players in the markets today are chasing short term gains despite the signals. I'd point to the housing crisis as a recent example, the biggest banks and funds were massively over valuing real estate and real estate derivatives because they were blind to the actual risks and saw what appeared to be free money.