[prostoalex]

Who will pay for this new tax?

If you're a company raising money, investors will want to be compensated for this extra cost, thus shifting the burden onto the company and raising the cost of raising capital.

If you're an investor who wants to liquidate, you'll be offered a price lower than fair market value, as buyer will want you to cover the tax portion.

Armed with this knowledge, the rational you will think twice before converting cash into financial equity instruments. Maybe you'll choose CDs, maybe bonds, maybe stocks of foreign companies that trade on exchanges that have no such requirements.

You could probably mitigate the HFT strategies by suggesting the market stay open for just a few hours a week - enough for buyers and sellers to match outstanding bids, not worth it for HFTraders to bother.