The Dow Jones Industrial Average surged to a new intraday all-time high on Monday, closing at a record as traders cheered the possibility of a U.S.-Iran agreement. Optimism around the potential deal drove broader market gains, underscoring how geopolitical developments are shaping investor sentiment.

A thaw in U.S.-Iran relations has been a key focus for markets, given Iran's role in global energy supply. Any deal could ease tensions in the Middle East and reduce risk premiums baked into asset prices. The rally reflects hopes for a diplomatic breakthrough after months of heightened rhetoric.

Oil prices moved lower alongside the stock market rally, as lower geopolitical risk typically weighs on crude. The move was consistent with the pattern of falling energy costs when supply disruption fears recede. The decline in oil added a tailwind for consumer-related stocks and transport sectors.

The record close suggests investors are pricing in a favorable resolution, though details of any potential agreement remain unconfirmed. If talks falter, markets could quickly reverse course. The coming days may bring further clarity as diplomatic discussions resume.

Some analysts caution that euphoria may be premature, given past failed negotiations with Iran. The absence of a formal deal leaves the market exposed to headline risk.