Having formerly worked for an NYSE Specialist firm the role of market making is incredibly important, but many large-scale HFTs today operate in ways that either stretch the legal boundaries or exploit regulatory gaps. Many practices arguably amount to market manipulation in spirit, even if technically legal. Candidly, the regulators are either too lazy, stupid, ill equipped or uninterested to do anything about it.
Does it really matter? I've done nothing but buy and hold at reasonable prices, and market manipulation has never affected my trades. This seems like finance bros fucking finance bros, which is solidly in the "who cares" category of my life.
Our 401k & pensions are managed by "finance bros"
I hope mine is not managed by someone dumb enough to keep handing money over to Jane Street on such a simple scheme. If they are that dumb, I need to move my money way more than I need Jane Street punished.
Good luck moving "your" money out of a shared pension plan.
For a defined benefit plan, I don’t need to care. For defined contribution plan, I care (but can usually choose investments). I personally only have 401k, IRA, and after-tax investments, no pension.