Step right up folks! It's time to play Wall Street's latest craze "Guess What Bill Ackman's Buying." Wait a second. Upon further thought, please don't. The game is way too dumb even for experts like us. Rumors that the Pershing Square hedge fund manager was taking a position in FedEx ( FDX) sent shares of the delivery giant up over 4% Tuesday to $103. The stir got started when Reuters reported that Ackman was asking institutional investors to commit $1 billion to two new funds by the end of next week with the sole purpose of diving into an unnamed business that is "simple, predictable, and free-cash-flow-generative and enjoys high barriers to entry." "We are launching two new co-investment funds PS V, L.P. and PS V International," Ackman wrote in a July 8 letter seen by Reuters. "Because of confidentiality considerations, it is not prudent for us to share the target company name with all of our 500+ investors." Hmmm. Tell us Bill. Is it bigger than a breadbox? Can we buy a vowel? Wait...do we have to answer in the form of a question? Yeah, the whole thing sure does make one wonder why all those Wall Street heavy hitters spent all that time and money getting their Ivy-league M.B.A.s when their investment strategy is simply to speculate on Bill's next big bet. And yes, Bill certainly makes big, big bets, so it is not hard to understand why folks would want to take a shot at front-running him. Not all of them work out of course -- see the debacles at Target ( TGT) and J.C. Penney ( JCP). But when Ackman goes in, he goes all-in and judging from Pershing Square's lifetime annualized return of more than 20% after fees, it's hard to argue with his success. (And judging from that recent Vanity Fair profile of the highly competitive Ackman, it seems best not to argue with him at all.) And despite what his Herbalife ( HLF) nemesis Carl Icahn may think, Ackman does not make his billion dollar wagers willy-nilly. Trust us, we've seen his slide shows. They're longer and more draining than your average Robert Altman movie. If Ackman's target is indeed FedEx, the other thing we learned on Tuesday is that the company does indeed have the "high barriers to entry" Bill desires. The company agreed to settle a lawsuit over claims it was "systematically overcharging" clients by billing for deliveries to businesses and government offices at higher residential rates, according to a filing in federal court in Memphis, Tenn. Take it from us. Not everybody can rip off their customers like that. It takes a wide moat around your business and that's exactly what Fedex and UPS ( UPS) enjoy when it comes to overnight shipping. Although there is one other option...Hold on! Is Ackman planning to buy the U.S. Postal Service? Oh Lord! Forget game show. That would be a reality show. Especially if he hires ex-JC Penney CEO Ron Johnson to star in it.