There are some really great points in this writeup from @AlexanderGerko, much of which I agree with. Nearly all retail trading today is internalized by a duopoly whose incentives are not to ensure best execution for retail clients. https://twitter.com/HideNotSlide/status/1356959713854914560

This does several things to markets, but one of those things is to take that flow away from lit markets and open competition. Markets should encourage open competition - how is that even controversial? Get retail flow on lit markets.

If Citadel and Virtu are truly providing best execution, they'll still be on the other side of the trade! If they're not, others will step in. Retail brokers SHOULD charge commissions, instead of hiding those costs in securities lending, PFOF and margin interest.

This will improve markets for ALL participants. Our markets are so focused on active day traders they have neglected the institutions that are TRULY retail - mutual funds and pension plans. We should ensure markets work best for them (and listing co's), all others are secondary.

Finally, I don't like the FTT proposal, but 5-10 bps won't have a huge impact. I do like how Gerko points out that while an FTT might impact VOLUME, that doesn't mean it will impact LIQUIDITY. A lot of people struggle with the difference, but volume is not liquidity.

Here's an example - the Flash Crash. That was an extremely HIGH volume event characterized by a complete LACK of liquidity. It's extreme, but illustrates the difference well. He's right that US markets are great at volume and churn - less so on liquidity.

Getting retail out of the dark and onto markets will substantially improve liquidity by increasing incentives to market makers, who are the most important determinants of liquidity. This is a great opportunity to reexamine this entire practice and fix it!