Outflows from U.S. stock funds accelerated mid-August after hopeful signs that they might be slowing down, according to the latest statistics from the Investment Company Institute. For the week ended August 22, investors pulled an estimated $4.48 billion from mutual funds that invest long-term in U.S. equities, substantially more than the $2.72 billion they withdrew the week before. Since the beginning of the year, investors have pulled more than $75 billion from U.S. funds.

Non-U.S. equity funds also took a beating, losing an estimated $1.40 billion in outflows for the week, almost three times the $557 million withdrawn a week earlier.

Bond funds attracted the most money of any category, but even they were off for the week. The funds took in $6.83 billion, down from the previous week's $7.59 billion inflow. Of the $6.83 billion, $5.91 billion went to taxable bond funds with the remaining $921 million going to municipal bond funds.

The biggest winners of the week were hybrid funds - those that invest in both stocks and fixed income securities. The funds raked in $2.41 billion, more than double the previous week's $953 million inflow.

All told, mutual funds logged a lackluster week, attracting a tepid $3.37 billion or 36% less than the $5.26 billion they drew in a week earlier.

The weekly fund flow estimates are derived from data covering more than 95% of industry assets, according to ICI. The statistics cover long-term mutual funds, those the ICI defines as investing in long-term instruments.