Investors worldwide poured a net $15.8 billion into bond funds in the week ended Oct. 8, marking the funds' biggest inflows in dollar terms on record in the wake of Bill Gross' departure from Pimco, data from EPFR Global showed on Friday.

The net dollar inflows were the biggest since records began in 2001, EPFR Global said. As a percentage of the funds' assets under management, the inflows were the biggest since the first week of February, the Boston-based fund tracker said.

Money market funds attracted $47 billion, their biggest inflows since October 2013, according to a Bank of America Merrill Lynch Global Research report, which also cited EPFR Global data.

Outflows of $12.9 billion from stock funds were the biggest in nine weeks, data from the Bank of America report showed. The outflows underscored the risk-off sentiment over the period.

A portion of the inflows into bond funds likely came from investors pulling money out of Pimco and redirecting it to rival bond fund managers, said Jack Rivkin, chief investment officer at Altegris in La Jolla, California.

The Newport Beach, California-based Pacific Investment Management Co oversaw $1.97 trillion in assets under management as of June 30.

"Money is flowing out of Pimco," Rivkin said. "It is a typical check-list reaction to a change in portfolio managers," he said, referring to the departure of Gross on Sept. 26 for rival Janus Capital Group. Gross, who co-founded Pimco more than 40 years ago, was replaced by Daniel Ivascyn.

The Pimco Total Return Fund, which Gross ran and which ranks as the world's largest bond fund, posted $23.5 billion in outflows in September, with the largest daily outflow occurring on the day of Gross' departure.

Rivkin said a portion of the inflows into money market funds may reflect institutional money managers' uncertainty as to where to redirect cash after withdrawing from Pimco. Money market funds are low-risk vehicles that are often used as a place to park cash.

Investment-grade bond funds attracted $12 billion of the net inflows into bond funds, according to the Bank of America report. Funds that mainly hold safe-haven U.S. Treasuries attracted $3.1 billion, marking their biggest inflows in seven weeks, data from the report showed.

While the net inflows into bond funds showed the degree to which Pimco's rivals attracted new cash, the Bank of America report said the net inflow figure was "likely overstated" since it did not account for Pimco's fund flow activity.

Japanese stock funds posted $1.7 billion in outflows, marking their biggest withdrawals in dollar terms on record, according to the Bank of America report. European stock funds also posted $1.7 billion in outflows, marking their sixth straight week of withdrawals.