Gross also praises Vanguard Group founder John Bogle, who designed many of the low-cost index funds popular with retail investors today.
"He's got a lot of investment common sense, recognizing decades ago that investment managers in composite couldn't outperform the market," Gross said.
Of course, for Gross, the exception is Pimco.
"If Bogle's concept of indexing was metaphorically similar to finding a cure for the cancerous devastation of high fees, then perhaps Pimco's approach could be similar to mapping the investment genome and using it to produce consistently high alpha."
But neither firm "has discovered a cure for the common cold," Gross quips.
El-Erian: 'Take some money off the table'
Pimco does, however, seem to be feeling under the weather lately. The Pimco Total Return fund(PTTRX), is down almost 3.5% this year.
And it's shrinking. Investors pulled out almost $37 billion so far this year -- forcing it to cede its title as the world's largest mutual fund.
Gross, known for his spirited investment letter insights packed with pop culture metaphors, is one of the most closely watched players on Wall Street.