Hedge fund magnate Bill Ackman is coming off the worst two-year stretch of his career, and he wants his clients to know he's learned his lesson.
Owing largely to a disastrous investment in Valeant, a pharmaceutical company that came under fire for its pricing practices and other issues, Ackman's Pershing Square Holdings saw returns for its $11.1 billion main fund tumble 13.5 percent net of fees in 2016, according to a report the company released late Tuesday.
That's coming off a 2015 loss of 20.5 percent for a fund that historically has done very well against market benchmarks such as the S&P 500. The fund has more than tripled the index's return since 2004, according to Pershing records.
The annual report gave Ackman the opportunity to offer a mea culpa for the loss and to explain to investors what he learned from the experience, with special focus on the Valeant investment.
"My approach to mistakes is that I personally assume 100 percent of the responsibility on behalf of the firm while sharing the credit for our success," Ackman said.