"We do not view this as an asset gathering horse race," said John S. Woerth, spokesman at the Valley Forge, Pennsylvania-based Vanguard Group. "It is, however, representative of the popularity of low-cost, broadly diversified index funds."
The Pimco Total Return Fund hit a peak of $292.9 billion in assets under management in April 2013.
The Pimco Total Return Fund delivered a net after fee return of 1.62 percent year-to-date through April, outperforming its benchmark by 38 basis points, Pimco said.
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Gross, the legendary bond manager long known as the 'Bond King,' exited Pimco suddenly last September for smaller rival Janus Capital.
Pimco has seen about $130 billion of net withdrawals from its open-ended funds since Gross' departure even as performance has improved.
Outflows from the flagship Pimco Total Return Fund, which Gross managed since 1987, have slowed to an average of $7 billion to $8 billion a month recently from $23.5 billion in September.
Pimco, which oversees $1.59 trillion in assets as of March 31, announced last week that former Federal Reserve chairman Ben Bernanke was joining the Newport Beach, Calif.-based firm as a senior adviser, as Pimco seeks to bolster its star power following the departure of Gross.