Citi Just Downgraded Bill Ackman's Pershing Square Stock to Sell, Citing a $45 Price Target Versus Its $60 Peak. Is PS Stock Overvalued After Its April IPO Rally?

Pershing Square Inc. (NYSE: PS), the investment firm founded and run by Bill Ackman, went public in April, and the stock has soared since then. It opened at $24 per share on April 29 as part of a combined initial public offering with the firm's Pershing Square USA fund. Since then, PS stock skyrocketed to a high of $60 per share on Oct. 7 -- a 150% gain at its peak.