Regis: I was Einhorn's best summer intern ever

Meet Regis Philbin, hedge fund intern.

Taking up a recent offer for a summer internship at David Einhorn's Greenlight Capital, television legend Philbin revealed what his day was like Tuesday on CNBC's "Fast Money."

"Yes, so I went up to the David Einhorn offices, met everybody," he said. "Happens to be a very nice guy. We had a long, long talk. And I tell you how it ended: They thought I was the best summer intern they ever had."

Last week, Einhorn said on air that he had been impressed by one of Philbin's winning stock picks and offered the former TV show host an internship.

Read MoreThe stock pick that landed Regis a summer internship

Known as "the hardest working man in show business," Philbin said that his duties at the firm consisted of doing legwork on three companies.

"I suggested to David that we call Micron Tech, MolyCorp, Lululemon, and we had some very interesting conversations with the Micron Tech people," he said. "And incidentally, I don't think it's going to bounce down much anymore. I think it's on its way to at least $30. I think it almost touched $29 today."

Philbin owns shares of Micron Tech, MolyCorp and Lululemon.

"Now, today MolyCorp was up 22 cents. MolyCorp never goes up that much," he said. "I'm lucky if MolyCorp goes up 2 cents once in a while."

Einhorn had been rumored to be short LULU, although his most recent 13F filing does not show a position.

Philbin said that they had called three different Lululemon locations—"and not one of them answered!"

"I'm still in the stock, but I'm very disappointed that they didn't take the calls when we made them, for crying out loud," he added.

—By CNBC's Bruno J. Navarro.