william ackman founder and ceo of hedge fund pershing square capital management speaks during the sohn investment conference in new york may 4 2015 reutersbrendan mcdermid new york july 11reuters  billionaire investor william ackman who had raised the biggestever special purpose acquisition company spac said on monday he would be returning roughly 4 billion to investors after failing to find a suitable target company to take public the news signals a setback for the prominent hedge fund manager who had initially planned for the spac to take a stake in universal music group at a time these vehicles were all the rage on wall street at the start pershing square tontine raised 4 billion in its initial public offering and wooed prominent investors ranging from hedge fund baupost group canadian pension fund ontario teachers and mutual fund giant t rowe price group but trouble soon arrived when ackman tried to take a 10 stake in universal music which was being spun off by french media conglomerate vivendi the us securities and exchange commission objected and ackman put the investment into his hedge fund instead