[conistonwater]

It's not a nice way of saying that, the "pool of bait" logic is totally wrong. There's a lot of nonsense written about high frequency trading on the internet, but for example Matt Levine's explanations are completely readable, correct, and on point (see the other comment).

[mrfredward]

If someone will pay to trade with you instead of someone else, you're definitely not getting the best price.

[SirLJ]

There is no free lunch... To paraphrase a friend from high school: "...when you start to play and don't know who the patsy is, usually it's you..." ;-)