Goldman Sachs predicts that the continued decline in stock buybacks could cause stock-market turmoil in the new year.

Stock buybacks declined 15% to $710 billion this year, according to a Goldman estimate. The firm expects another 5% drop in 2020, but a bigger decline could cause trouble, CNBC explained.

The demand created by buybacks has outpaced demand from other sources, such as mutual funds, since 2011, giving repurchases increased importance in the U.S. markets, according to Goldman.

Otherwise, Goldman is bullish on equities next year, predicting a 7% gain for the S&P 500, CNBC explained.

If share repurchases fall more than expected next year, it could lead to slower earnings per share growth and increased volatility. The demand created by buybacks has outpaced demand from other sources, such as mutual funds, since 2011, giving repurchases increased importance to the U.S. markets, according to Goldman.

“A significant decline in buybacks would dramatically shift the supply-demand structure for U.S. equities,” the note said.

Meanwhile, investors apparently are sensing trouble in the wind.

Individual investors reportedly are fleeing stock funds at the fastest pace in decades despite what may be the best year for stocks since 2013.

Investors have pulled $135.5 billion from U.S. stock-focused mutual funds and exchange-traded funds so far this year, the biggest withdrawals on record, according to data provider Refinitiv Lipper, which tracked the data going back to 1992.

Investors have shifted hundreds of billions of dollars into bonds and money-market funds all year long as recession fears rang and tariff wars lashed markets, analysts told the Wall Street Journal

The exodus to traditional safe harbors of investing is also a sign that investors aren’t chasing the stock market’s strong performance, seemingly setting record highs on a daily basis. This suggests major indexes like the S&P 500 still have plenty of room to run after a decade-long rally, WSJ.com reported.

“There’s not a lot of faith in this market,” Scott Wren, a senior global equity strategist at Wells Fargo Investment Institute, told the Journal. “There’s no chasing going on. Usually before you hit the top in a cycle, there’s a lot of chasing and fund flows are higher.”