[esmi]

Personally I waffle on this myself. My instinct tells me it’s bad but then I try to decide what trading cadence I would limit it to. Assume there is a CEO who wants to do something nefarious to manipulate the stock price. If they make a decision how fast can a company actually act on it? Would or could they make the company act on 1 hour boundaries? Even if we limited trades to once per week is that the long term we want a CEO to consider? At what time frame does a stock stop being a stock and convert to something else? Then I decide even by minute trading is not really something that management can even consider, even if they want to, so there is really no point to artificial limits imposed by law and take a more laissez faire attitude.

[ncmncm]

Don't limit cadence. Just tax transactions, and cadence will limit itself.

[esmi]

I waffle on this one too. Institutions that do HFT have a huge capital cost and pay large fees before they even make their first trade. They also employ programmers, traders, etc. Basically, these taxes are going to need to sum to something really big to dissuade them. Too small, they ignore it. Medium, the market will just consolidate. Large, you'll stop HFT, but at what consequence? The probability of unintended consequences is high.

This is when I decide I don't really understand the market as well as I think, and I should stop solving the world's problems, and go back to designing circuits.

[ncmncm]

A tiny tax on each order (bid, ask) entry would cut the total volume of orders by a huge factor, cost them only a small fraction of their takings, and probably fund free college for everyone in the US.