Such a move would probably work in the NSE,but end up killing local investors interest, in the stock market, which was the ultimate aim of the government, but not the property market like land or houses. This is simply because of demand and supply.
There are too many people with pent up demand and land and buildings /houses are in very short supply.
This would mean that the buyers would simply avoid the tax by adding it on top of the property prices. This would in effect make the property prices unaffordable, making nonsense of the government efforts of making housing affordable and with the current housing crisis, your guess is as good as mine as to what the majority of Kenyans would be able to afford.....

Kenyan politicians are allergic to anything that can hurt their interests. So I betcha that thing aint coming soon. At least not until ODM comes to power as they have not had too much time to accumulate large holdings.

Besides, The son of Ngina has to protect his family interests....

Okay let me put it this way, in which country is the CGT being levied, on which particular capital transactions and how has is it going/working? Is there a good story about CGT for any economy thus far?