"2019 is off to a strong start," Ackman wrote in a presentation detailing his Pershing Square Capital Management's portfolio and performance. The S&P 500 stock index has gained 9.7 percent this year.

"We expect our portfolio to compound earnings and intrinsic value at a much higher than the market," Ackman wrote in the presentation.

The firm now oversees $7.9 billion, with the bulk of assets located in Pershing Square Holdings. His private hedge fund, Pershing Square International Ltd, oversees roughly $1.2 billion.

Mortgage lender Fannie Mae common shares have surged 140.6 percent while Freddie Mac shares have climbed 130.2 percent to power the portfolio, Ackman wrote. Chipotle shares gained 37.5 percent and United Technologies shares have climbed 16.4 percent, he added, noting that all holdings are in the black.

For Pershing Square Holdings, the first weeks of 2019 mark the strongest returns since 2014, when the portfolio returned 40.5 percent.

Over the last four years, Ackman has lost money and he has vowed to make it back by reshaping his organization.

(Reporting by Svea Herbst-Bayliss; Editing by Steve Orlofsky)

By Svea Herbst-Bayliss