No, prices are set by buyers and sellers obviously. Except in this case, most people are negative on Yahoo but don't know about Alibaba, nor do billionaires who could move the stock believe Yahoo could dispose of Alibaba at reported levels. In fact, Yahoo's stake is bigger than the initial amount of stock the IPO will offer.

This could all change of course.

I think Alibaba is private, and its "valuation" is just an analyst's estimate. That estimate could be an old figure, so the article is using inconsistent data.

Or people who actually live overseas. I hear there is quite a few of them.

Alibaba hasn't IPOed yet.

but yahoo is overseas stock for them. so?

You can buy stock overseas if your broker offers it. And you don't need to be a billionaire.

and it is expensive as hell, complicated and may result in taxes in several countries. thats why almost nobody does