Key TakeawaysHoward Hughes shares jumped after Bill Ackman's investment firm offered to buy the remaining stake in the company.Ackman's Pershing Square already owned 38% of Howard Hughes as of Nov. 14, according to an SEC filing.The move would create a Pershing subsidiary to merge with Howard Hughes, giving current investors an offer of $85 per share. Billionaire Bill Ackman’s investment firm Pershing Square has offered to buy the remainder of real estate developer Howard Hughes Holdings (HHH) for $85 per s ...