The Dow Jones Industrial Average and the broad-based S&P 500 each rose 0.4 percent, while the tech-heavy Nasdaq Composite Index rose 0.5 percent.
It may be that the market is underestimating the significance of the disruptions affecting the global economy, analyst Michal Rosen told CNBC.
Early on Monday, reports emerged in U.S. media that the US and Iran were discussing a 45-day ceasefire through intermediaries. However, a denial came from Tehran shortly afterward via state-controlled media.
Oil prices rose slightly during the day. At 10 p.m., WTI crude traded just above $112 a barrel, while Brent crude traded just above $109 a barrel.
