Are you thinking it’s a flat tax?

It would be percentage of the price…

Buy 10 at $100 and pay 10%, that’s $10.

Later you sell 10 at $50, that’s $5.

If it was $200, pay $20.

Profit or lose, get taxed when you trade.

It incentives long term holding which is better for the company anyways and stabilizes prices.

And pretty much elimate all the day trading bullshit that makes companies focus on constantly improving profit margins no matter what the long term repercussions are.

Companies would want to show sustained long term growth to intice investors who could potentially keep the stock for years.