Investment pioneer Jack Bogle modestly says he’s not worthy of being anyone’s hero, much less an idol to billionaire investor Warren Buffett.

Buffett, speaking Saturday at the 53rd annual general meeting of Berkshire Hathaway, said the Vanguard founder "probably (has) done more for the average investor than" anyone. 

"It was not in the interests of Wall Street to have the development of index funds, because it brought down fees dramatically. When Jack started, very few people, certainly Wall Street did not applaud him. He was the subject of some derision. And now we're talking trillions when we get into index funds," Reuters cited Buffett as saying.

"Jack at a minimum has saved, in the pockets of investors, he's put tens and tens and tens of billions into their pockets," Buffett said.

Bogle said he wrote Buffett a letter to thank him, but added he's "an ordinary guy."

"I'm not a hero," Bogle, 88, told CNBC. "I'm just an ordinary guy who has tried to do my best for investors and who gave a damn about the people who were investing and wanted to make sure they got a fair shake," said Bogle, the founder of the Vanguard Group, the world’s largest provider of mutual funds with $4 trillion in global assets under management.

"If that's heroism, then so be it."

Bogle said indexing is here to stay, and feels good about getting "the ball rolling" years ago.

"I don't look at the traditional funds as being threatened," Bogle said, when discussing the rise of ETFs. "They're total international, total bond market. Those are the dominate forms of investment for the traditional funds like ours. That's where the money is going mostly."

Earlier this year, Buffett also praised Bogle in his annual letter to Berkshire Hathaway Inc. shareholders.

The pioneer of indexing was once an outcast in the investment world as he eschewed riches to provide real value to American investors, Buffett wrote.

“In his early years, Jack was frequently mocked by the investment-management industry,” Buffett wrote. “Today, however, he has the satisfaction of knowing that he helped millions of investors realize far better returns on their savings than they otherwise would have earned. He is a hero to them and to me.”

Bogle started the indexing revolution for retail investors in 1976 when he launched the Vanguard 500 Index Fund. The fund, which just passed its 40th anniversary, had $205 billion in assets as of Aug. 31, Bloomberg reported.

(Newsmax wire services contributed to this report).