David Tepper wasn't joking when he said it was "nervous time" for the stock market.
The billionaire head of the Appaloosa Management hedge fund rattled the markets in May, when he told attendees at the SALT Conference in Las Vegas that he was paring back his equity positions.
"I'm not saying go short, I'm just saying don't be too fricking long right now," he told attendees in remarks that went viral and immediately sent a shiver into the market.
Judging by his most recent quarterly filings with the Securities Exchange Commission, Tepper wasn't trying a sleight of hand, wherein he would try to get investors to sell so he buy at reduced prices.
Read MoreTepper on the market: 'Nervous time'
No, he was selling. Tepper, who made an eye-popping $3.5 billion in 2013, shed multiple positions.
He sliced his holdings in the Powershares QQQ Trust exchange-traded fund, which tracks the Nasdaq tech-stock index, by two-thirds. He pared down his holdings in the SPDR S&P 500 ETF, which tracks the broad index, by more than 80 percent. And he dumped his entire stakes in such companies as JPMorgan Chase, Beazer Homes and Ingersoll-Rand, while cutting in half his holdings in Dow component DuPont.
While the 13f filing is backward-looking and may not reflect where Tepper stands now, it provides a look into his thinking during a quarter in which the market, as measured by the S&P 500, actually rose 4.6 percent.
To be sure, Tepper wasn't cutting across the board.
He sharply increased his stake on social media giant Facebook, raising his holdings seven-fold, and he upped his General Motors holdings by about 50 percent. He also took a much larger stake in home furnishings company Masco and added to his position in online bidding site Priceline. His largest holding as of the end of the second quarter was American Airlines.
Tepper did not immediately respond to a request for comment.
However, in May, as he was cutting his positions, he expressed a measured approach to investing in the current climate that differed somewhat from many of the strongly bullish statements he's made over the past several years.
"I think we're OK," he said at SALT, "but listen, there's times to make money and there's times not to lose money. This is probably (a time when) you're supposed to think about preserving some of your money. If you're 120 percent invested, it's probably too much. You can still be long, but you probably should have some cash."
—By CNBC's Jeff Cox