Many of the traders I talk to are wondering what Bill Ackman could be thinking.

Ackman is a hedge fund manager, the founder and CEO of Pershing Square Capital Management, which has about $11 billion under management. Ackman is considered a contrarian investor who tends to buy when companies are down, and an activist investor who sometimes takes a role in managing companies he invests in. He has achieved incredible success by some measures and has a reported wealth of about $1.4 billion.