Fink said he's certainly not denying that confidence is up since the election.
"I'm not suggesting this is short-lived or long-lived, because I don't know yet," he said in a "Squawk Box" interview. "We are seeing better numbers out of Europe, better potential numbers here in the United States, and probably better numbers in Japan."
But he said, "The story is not as euphoric as it feels in the U.S. equity markets."
Since the election, based on Thursday's close, the Dow Jones industrial average was up 8.5 percent, the Nasdaq was up 6.8 percent, and the S&P 500 was up about 6.1 percent.
The chairman and CEO of the world's largest asset management company, with $5.1 trillion in assets under management, said he could paint a bullish scenario or a more cautious scenario for U.S. stocks based on the execution of Trump's policies.
The wildcard, according to Fink, would be how quickly Trump's pro-growth policies — such as tax cuts — get adopted, and how ambitious they turn out to be. There's not enough information yet, he added.
Other factors to consider, Fink said, are whether those policies significantly increase the federal deficit or heighten tensions with key trading partners, which would be headwinds for stocks.
"We have high expectations for ... Trump's administration to effectuate some of the policies that he says he's going to set forth, whether it's tax policy or infrastructure," Fink said.
He did warn, however, "It always takes longer and is more difficult to roll out."
Regardless of Trump's policies, the U.S. economy has "growth momentum going on already," Fink said.
Fink appeared on "Squawk Box" shortly after BlackRock reported mixed quarterly results. BlackRock's adjusted earnings beat estimates, but revenue fell short of expectations.
"I don't see as much transformation in regulation [under Trump]. And in fact, banks are going to be in very good shape going forward, even with a modest change in regulation," he said.
In an October appearance on "Squawk Box," ahead of the election, Fink warned investors about using passive money management strategies, such as exchange-traded funds, to try to achieve more aggressive returns usually associated with active management.
At the time, Fink also said retirees should stay in stocks because they're living longer and need to generate the kind of returns needed to live on in retirement.
As markets were crumbling at the beginning of last year, Fink had told CNBC he thought there was "not enough blood in the streets," and predicted another 10 percent drop. The market did about half that, bottoming out on Feb. 11, 2016.
On CNBC Friday, Fink reflected on that call, pointing out that he had advised investors to stay in stocks and not try to time the market.
Correction: A BlackRock spokesperson said Fink was referring to global investors when he said "the story is not as euphoric as it feels in the U.S. equity markets."