Microsoft buys near 4% stake in London Stock Exchange

Buying equity in your customers so they go with your cloud is a new level of embarrasing.

The question is not how and what but why? Is the RoI of IT even lower than London exchange ?

NASDAQ recently made the announcement to go all in on AWS, I think. I know this is not the same thing but may be something like that or a partnership of some sort is coming up?

Can someone please explain to me how can a company by stake in a stock <i>exchange</i>?<p>How can an exchange even have stocks for sell?<p>How do they profit? What will MS gain from it?