(Bloomberg) -- California Public Employees’ Retirement System, the biggest US pension fund, lost 6.1% on its investments in the latest fiscal year, its worst performance in more than a decade.

The drop was driven by a 13.1% decline in publicly traded stocks and 14.5% slide in fixed-income securities, according to preliminary results posted Wednesday on Calpers’ website.

“Our traditional diversification strategies were less effective than expected, as we saw both public equity and fixed-income assets fall in tandem,” Chief Investment Officer Nicole Musicco said in the statement.

The pension fund’s private equity and real assets, which are a smaller part of the portfolio, delivered positive returns of 21.3% and 24.1%, respectively. Those figures, however, are as of March 31 and don’t fully reflect the recent sale of $6 billion of private equity assets, a portion of which will be included in fiscal 2023 results, according to Musicco. She declined to forecast how the transactions, first reported by Bloomberg, will change Calpers’ bottom line.

“It’s hard for me to predict anything at this point,” Musicco said in a press briefing. “I can say with confidence that what’s going on with that portfolio is top of mind for us and we feel very well diversified within it.”

Read more: Calpers Unloads Record $6 Billion of Private Equity at Discount

The last time Calpers reported a negative return was in 2009, in the wake of the financial crisis, when the portfolio plunged 23.4%.

The annual return target for Calpers is 6.8%. The fund’s five-year average returns are 6.7%. The fiscal 2022 loss leaves Calpers with 72% of its long-term funding needs. 

Calpers manages about $442 billion and serves roughly 2 million current and former public employees, including city, county and other government officials. The California State Teachers’ Retirement System, the second-largest pension with $314 billion as of May 31, hasn’t released its fiscal 2022 results.

(Updates with private equity sale in fourth paragraph, Musicco comments in fifth.)

©2022 Bloomberg L.P.