Well, the scoreboard has spoken and might continue to speak until some more jobs are shed and all those who applied for IB licenses recently find it futile.
Collection/Admin. is the issue. It is just messy. Disputes from the smallest investor to the largest.
More (short/medium) perspective is; commodities down, exports down, tourism down. The NSE has held up the current account with FX for two years straight. Throw this under the bus too and we'll be calling in that IMF SCF real soon.
So, without much ado I say a transaction tax. Accommodate KRA somewhere in the commission on the Buy & Sell. The brokers are used to collecting the other fees already.
To mitigate the rise in costs from the above, then NSE/CMA continue looking into structural inflation - like how they centralized payments at the CBK.
The biggest folly in all this is making estimates on turnover. This is wealth, not income. There are investors who are so underwater that CGT does not even occur to them, unless certain stocks go up by over 300%!
Kwa hayo, buy laggards and battered stocks. That's where regular trading might continue to occur - mitigation. Blue chips will be tricky on fair value.