Lloyd Blankfein doesn't see another tulip mania in the markets, but he does see some cause for concern.
"When yields on corporate bonds are lower than dividends on stocks, that unnerves me," the Goldman Sachs chief executive said during an interview Wednesday that was broadcast at a European banking conference in Germany and on the internet.
"The biggest problem, the anxiety that people have, is non-specific to what asset we are pointing to but the general feeling that things have been going up for too long," he said.
He added that it didn't feel like a tulip mania, a reference to a 17th-century run on tulip bulbs in the Netherlands that has become a symbol of market excess.
But, of course, you never really know until you know, he said. "When something happens, 80 percent of the world will remember knowing it … in hindsight."
Blankfein also talked about his continued hope for the Trump administration's ability to push its agenda through, despite some initial disappointments.