Didi is not Uber's competitor any more. Didi acquired Uber China, is an investor in Uber, and owns Uber shares. So does Uber in Didi. They don't compete directly in any major market at this moment.
They do compete by proxy, like in Brazil, where Didi invested $100m in "99".
I guess we can say that Didi owns everything then...
That actually makes perfect sense. Both of them realized they couldn't make any money without becoming a cartel and colluding.
> they don't compete directly in any major market at this moment
Emphasis on "at this moment".
Could you confirm/cite a source that didi owns shares in uber?
My understanding was that uber got ~20% of didi shares in exchange for ceding the Chinese market.