Veteran analyst Ed Yardeni thinks the "roaring 2020s scenario" could soon be back on track.

Yardeni's assessment in his Thursday note followed a third straight day of gains in major US stock market indexes.

The S&P 500 fell as much as 12% from April 2, when President Donald Trump announced new, sweeping tariffs against trade partners.

On Thursday, the index was about 3% lower since that day, after weeks of wild gyrations due to the president's shifting positions on policies. Market volatility subsided in recent days after President Donald Trump walked back some of his criticism of Federal Reserve Chair Jerome Powell and signaled easing tensions with China over trade.

"We still believe that the latest correction in the S&P 500 bottomed on April 8, a day before Trump basically postponed 'Liberation Day,'" Yardeni wrote. Trump put his new tariffs on hold for 90 days as US negotiates trade deals.

The Trump administration's new tariffs on trade partners and shifting policy positions have injected high uncertainty into the economy and financial markets this month. The political changes contributed to wild market swings and an erosion of investor confidence in US assets, including Treasurys and the dollar.

Bears were out strong, which probably rattled the Trump administration, Yardeni told CNBC on Thursday.

"What's really happened is that we had some extraordinarily pessimistic sentiment in the stock market, and I think those vibes got to the White House," he told the network.

"I think the White House blinked. I think it's pretty clear that, between the bond vigilantes and the stock vigilantes, that the White House understands that they can't take too hard a line because both markets will fight their intransigence," he said.

To be sure, Yardeni doesn't think the tariff war is over.

He wrote that trade deals will need to be inked soon for the stock market to sustain its current bounce.

Companies are also voicing concerns about the economy in the current results season.

Some companies — including Alaska Air, Southwest Airlines, and recruitment firm PageGroup — have started withdrawing or withholding guidance for this year.

On Wednesday, Southwest Airlines CEO Bob Jordan said on an earnings call that the year started out "very strong." He said demand, especially for leisure travel, weakened as the quarter progressed.