A bond bubble is coming, warns Goldman Sachs CEO Lloyd Blankfein.

"I think that is one of the big risks that are looming out there right now," Blankfein said at The New York Times Dealbook conference, according to Fortune.

Ongoing low interest rates have prompted companies to take on massive amounts of debt. Indeed, this year has seen a record amount of corporate debt issued. Record-low rates are good for borrowers, but may not be good for corporate-bond buyers.

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.

"Someone is buying that debt," Blankfein said, Fortune reports.

"What's going to happen when growth picks up and interest rates rise? There's going to be a reversal and people will have losses."

Economic recovery that will prompt those rising rates might be imminent.

More executives seem to be discussing how to position their firms for growth, and less about muddling through the recession, he said, according to Fortune.

"I think we're where we were in 1944. The war isn't over yet, but pretty much everyone sees the end soon."

Blankfein isn't the only one warning about a corporate bond bubble. Many experts believe bonds are already in bubble territory and have become overpriced, although some believe fears are overblown, the Financial Times reports.

The yield on the S&P International Corporate Bond Index dropped from 4.5 percent to less than 3 percent this year.

"We sold everything we had in corporate bonds last month and are sitting on lots of cash for now," Charlie Kerr, head of fixed income at Newscape Capital, told the Times. "For now we don’t think it’s a good time to get back in."

Editor's Note: I Wish I Were Wrong — Economist Laments Being Right. See Interview.