Bill Gross, who runs the world’s biggest bond fund at Pacific Investment Management Co. (Pimco), raised holdings of Treasurys and government-related debt in January as the U.S. bond market had the best start to a year since 2008.

The proportion of the securities in the $237 billion Total Return Fund was 46 percent last month, compared with 45 percent in December, according to the company’s website.

Mortgage debt accounted for 36 percent in January, compared with 35 percent the previous month.

Pimco doesn’t comment directly on monthly changes in holdings or specific types of securities within a market sector. The company is a unit of the Munich-based insurer Allianz.

The Total Return Fund gained 1.8 percent as of Feb. 7, beating 87 percent of peers. The fund last year lost investors 1.9 percent, the most since 1994, while falling behind 65 percent of peers.

Treasurys returned 1.6 percent in January, the best start to a year since advancing 2.5 percent in 2008, according to the Bank of America Merrill Lynch U.S. Treasury index.

The Total Return Fund had estimated withdrawals of $3.5 billion in January, after suffering its worst year of net redemptions in 2013,
research firm Morningstar said. The fund had redemptions of $41.1 billion last year.