(Bloomberg) -- Many hedge fund managers would celebrate if they posted a 20% annual return, as Renaissance Technologies’ biggest fund did last year, beating industry benchmarks. Yet its customers keep heading for the exits.

Redemptions from the firm -- one of the world’s biggest, oldest and most sophisticated hedge fund operators -- have swelled to about $14.6 billion across its three public funds over the past 14 months, according to investor documents seen by Bloomberg. 

The mound of money leaving Renaissance -- which oversaw $75 billion at the end of 2019 -- would be enough to force many mid-size money managers to close shop. It’s more than what’s managed by some prominent industry players, such as ExodusPoint Capital Management. 

The withdrawals show a reckoning isn’t over after Renaissance’s algorithms misfired when the pandemic started unfolding in 2020, inflicting losses of 19% to 31% in its trio of funds by the end of that year. Gains since then have been too slow to stanch outflows. Some investors aren’t willing to stick around for what could be another volatile period -- with the Federal Reserve set to battle the steepest inflation in a generation with a series of rate increases.

A representative for Renaissance declined to comment.

Read more: Renaissance Suffers $11 Billion Exodus With Meager Quant Returns

Bloomberg has been tracking the firm’s monthly redemptions since the tail end of 2020. Though the bulk of the money left before mid-2021, some $3.75 billion has followed since. Customers asked to redeem $900 million in December, and an additional $650 million this month, the documents show. They could still walk back those requests. 

The pandemic has marked a change in fortunes for Renaissance, the long-revered pioneer of quantitative investing founded by codebreaker Jim Simons in 1982. For years, outside investors were drawn to the firm famous for operating the legendarily exclusive Medallion fund, open only to current and former Renaissance employees. But for customers that fund’s gravity-defying performance added salt to the wound in 2020, as they watched it soar 76%, making Simons one of the hedge fund world’s top earners.

Read more: Simons makes billions while Renaissance investors fume at losses

The firm has long told investors that its public funds trade differently than Medallion, said Nick Patterson, a former Renaissance executive who’s now a senior computational biologist at the Broad Institute of MIT and Harvard. 

“But a lot of investors didn’t believe them,” Patterson said. Now “after the very bad results in 2020, I think a lot of people realized, ‘Oh, when they said the fund wasn’t Medallion, it’s true.’”

Altogether, losses and redemptions have left Renaissance running around $50 billion -- most of it, the firm’s internal cash. 

“As long as Medallion is doing OK, the company isn’t remotely in any danger,” Patterson said.

While all three public Renaissance hedge funds posted double-digit returns in 2021, much of that came in the last month of the year. None of the funds beat the S&P 500 Index’s 27% tear -- though they all outperformed the 7.5% gain in the HFRI Asset Weighted Composite Index.

The trouble with quant funds is that, because algorithms rely on historical data to decide what and how to trade, they can struggle to navigate uncharted terrain. 

Renaissance’s beta models, which help determine portfolio exposure for its public funds, misfired in March of 2020 and “have not performed as expected” during that volatility, the firm said in a filing at the time. The funds were under-hedged during that month’s collapse and later over-hedged as markets rallied from April through June. That happened because its trading models “overcompensated” for the original trouble, the firm told investors in September 2020. 

The pandemic’s toll on Renaissance is now worse than what it suffered in the 2007 subprime mortgage crisis, when its Institutional Equities Fund had to sell assets at fire-sale prices. That fund sank 16% in 2008, its second-worst year after 2020. 

After its losses early in the pandemic, the firm said it was “vigorously exploring a number of ideas on how to improve both the beta models and the control systems that make use of these models.”

Renaissance hasn’t added commentary addressing its performance in its more recent investor letters. 

Read more: Renaissance Says Quant Models Misfired During March Mayhem

Most of the cash was pulled from Renaissance’s biggest hedge fund, its Institutional Equities Fund, also called RIEF. The combination of redemptions and performance has led to its assets shrinking by 40% between December 2019 and November 2021. Meanwhile, the Renaissance Institutional Diversified Alpha fund, dubbed RIDA, and Institutional Diversified Global Equities funds, or RIDGE, have lost 67% and 49% of their assets, respectively.

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