> If our intention is to kill HFT (and it probably should be), we could simply levy a very tiny transaction tax on trades. It would instantly render the practic

> If our intention is to kill HFT (and it probably should be), we could simply levy a very tiny transaction tax on trades. It would instantly render the practice unprofitable. That would also kill a lot of mutual funds, exchange-traded funds, asset managers, and others. These depend on the availability of frequent rebalancing of portfolios at low transaction cost. Add in a tax to this and you penalize it significantly.