oh, well, if you're a speculator, often you really do lose money to hfts because they're better speculators than you, but it's unclear why anybody outside your immediate family should care about that

if you're an investor, otoh, the lower spread and greater liquidity means timely execution costs you less, not more. you aren't paying them for liquidity; they're paying you, or rather you're paying them, but much less than the spread you'd've paid an old-style open outcry market maker

(do you even remember markets before decimalization? minimum spread 12.5 cents)

of course you do need to execute intelligently; you can't just plop a million-dollar order in a hundred-million-a-day market and expect the market not to move against you

> of course you do need to execute intelligently; you can't just plop a million-dollar order in a hundred-million-a-day market and expect the market not to move against you

It's fine for the market to move against big orders, I just want the movement to, like, take one second. I don't want anyone to change their position in response to an order that hasn't even resolved.

> (do you even remember markets before decimalization? minimum spread 12.5 cents)

Well I'm not suggesting we undo that.

> if you're an investor, otoh, the lower spread and greater liquidity means timely execution costs you less, not more. you aren't paying them for liquidity; they're paying you, or rather you're paying them, but much less than the spread you'd've paid an old-style open outcry market maker

In this scenario I'm a long-term investor so the cost means nothing to me. So it's a matter of whether I want HFTs to profit, and I don't, because their actions are often not win-win. If HFT worked somewhat differently I wouldn't mind them the same way.