For Ackman's investors, last year's increase returns the hedge fund to form with double digit gains after an interruption in 2022 when fears about interest hikes, runaway inflation and geopolitical flashpoints sent stocks tumbling.

Pershing Square Capital Management lost 8.8% in 2022 but gained 26.9% in 2021, surged 70.2% in 2020 and climbed 58.1% in 2019.

The firm did not say what fueled last year's rise though long-time portfolio company Chipotle Mexican Grill climbed more than 63% while Google parent Alphabet, a position Ackman added to the portfolio last year, rose 55%.

Ackman vowed in 2022 to retire from being a vocal corporate activist pushing change at corporations, but his investment moves, which he often announces on X, continue to be closely followed.

While investors fretted about high inflation and a possible recession at the start of 2023, the stock market powered higher late in the year amid hopes for interest rate cuts as soon as this year.

(Reporting by Svea Herbst-Bayliss; Editing by Sandra Maler and Shri Navaratnam)