(Bloomberg) -- Shares of Bill Ackman’s Pershing Square USA Ltd. plunged 18% in its debut after the combined initial public offering for the closed-end fund and his alternative asset manager raised $5 billion.Most Read from BloombergNorth Korea Confirms Suicide Rule for Soldiers Ukraine CapturesUAE Quits OPEC as War Upends Oil Markets and Gulf Tensions RiseJunior Bankers Sick of Grunt Work Build $2 Billion AI Tool to Do the Job80 Seconds of Big Tech Earnings Will Decide Stock Market’s FateTrump B