Ackman’s IPO Dream Implodes From $25 Billion to Zero in Weeks BloombergBill Ackman Abruptly Withdraws Planned I.P.O. The New York TimesWatch Bill Ackman’s IPO Dream Shrinks From $25 Billion to Zero BloombergBill Ackman’s Pershing Square withdraws IPO as demand for offering waned CNBCHere’s What Investing $1,000 in Billionaire Bill Ackman’s Portfolio Could Have Made You This Year Yahoo Finance