A blockbuster year for stocks and other assets perceived as risky helped hedge funds post their strongest performance since 2009 last year, though they lagged well behind the broader stock market, according to a closely watched performance gauge.

The HFRI Fund Weighted Composite Index gained 1.8% in December, leaving it with a 2019 rise of 10.4% — the strongest since a 20% rise in 2009, according to HFR, a Chicago-based hedge-fund data and analysis firm.