United Stocks closed sharply higher, rebounding after last week's sell-off, as investors took Crimea's widely expected vote to secede from Ukraine in stride.
At the closing bell, the Dow Jones Industrial Average rose 181.55 points, or 1.13%, to 16,247.22.
The S&P 500 advanced 17.70 points, or 0.96%, to 1,858.83, while the tech-heavy Nasdaq Composite Index gained 34.55 points, or 0.81%, to 4,279.95.
The gains came despite the rise in tensions over Ukraine, with the United States and Europe announcing sanctions against key Russian and Ukraine figures to punish their support for the Crimean breakaway.
Mace Blicksilver, a director at Marblehead Asset Management, said he was surprised by the strength of the rally.
But while the Ukraine events of the last 24 hours pointed to continued geopolitical division, there had been no surprises, he said.
Still, the rally likely will not last, Mr Blicksilver warned.
"It doesn't look like we're about to start another leg of a bull market here," he said.