William Albert Ackman (born May 11, 1966) is an American investor, hedge fund manager, and philanthropist. He is the founder and CEO of Pershing Square Capital Management, a hedge fund management company. Ackman is considered a contrarian investor but he considers himself an activist investor. Research published at The University of Oxford characterizes Bill Ackman's activities with Canadian Pacific Railway as paradigmatic of "engaged activism" – which is longer term in nature with correlated benefits to the real economy, as distinct from shorter term "financial activism". Wikipedia
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