Fund investors began the new year by pulling $13.1 billion out of mutual funds and exchange-traded funds that hold US stocks over the first full week of 2020, the largest pullback from the domestic stock market since September, according to data released Wednesday by the Investment Company Institute.

At the same time, investors sent approximately $24.7 billion into funds that hold taxable or municipal debt, the largest single-week inflow into bonds since 2013. The retreat from the US stock market comes as the benchmark S&P 500 index continues to post record highs after jumping nearly 30% over the course of 2019 thanks to a partial trade deal with China and expectations that the Federal Reserve will not raise interest rates any time soon. The S&P 500 index is up nearly 2% since the start of the year, more than double comparable indices in developed markets such as Europe and Japan.