The Man Behind Alibaba’s Eventual I.P.O.

JPMorgan Chase has called. So has Goldman Sachs and Morgan Stanley. Joe Tsai’s phone is ringing off the hook these days, and you would be forgiven if you have never heard of him.

Mr. Tsai is not even a chief executive, but he has become arguably the most sought-after executive in the world by Wall Street for one reason: He holds the keys to what will most likely be the largest initial public offering of this generation — Alibaba, the Chinese e-commerce giant.