Wealthy investors are poised to put at least $90 billion into hedge funds next year, even after returns have largely been lackluster this year, research firm eVestment said on Tuesday.

Fresh demand from pension funds, endowments, and insurers looking for alternatives to traditional stock and bond holdings will fuel next year's flows, the researchers wrote in a report.

"Will institutional investors maintain their investments and continue to allocate more to hedge funds in 2015 ... The short answer is yes," they wrote, adding "We expect asset flows into hedge funds of at least between $90 billion and $110 billion in 2015." Hedge funds manage roughly $3 trillion in assets.

The appetite for hedge funds remains strong even after the $300 billion California Public Employees' Retirement System, the largest U.S. pension fund, said in September it was pulling out of hedge funds because they are too costly and complicated.

Hedge funds took in roughly $112 billion in new money this year even though returns have been paltry, with the average fund returning roughly 4 percent this year through November. As hedge funds posted low single digit returns, the stock market raced to a series of fresh highs and the Standard & Poor's 500 index gained 12.8 percent since January. Last year, investors added $62 billion in new money to hedge funds.

Researchers said they expect the pace of flows into stock-oriented hedge funds to slow slightly next year while multi-strategy funds that bet on mergers, acquisitions, and spin-offs may pull in more new money next year compared to this year, when investors added $48 billion.

"Their diversity makes them a natural preference for long-term institutional assets coming from traditional strategies," the researchers said.