The reaction was not limited to stocks.
Oil prices, which had surged as traders worried that the conflict could disrupt energy supplies and threaten the Strait of Hormuz, moved sharply in the opposite direction. Brent crude fell about 4.7%, while West Texas Intermediate dropped roughly 5.1% during Monday’s trading.
That decline was particularly important for investors because higher gasoline and energy costs can quickly spread throughout the economy.
When oil becomes more expensive, transportation, manufacturing and other energy-intensive industries can face higher costs. Those increases can eventually reach consumers, creating another headache for policymakers already watching inflation closely.
Trump’s latest move therefore delivered Wall Street something it had been desperately looking for: a possible path away from escalation.
The president said he had paused planned military action while diplomatic efforts continued. Trump has also pointed to negotiations involving Iran and regional countries, including efforts aimed at reopening the Strait of Hormuz, a critical passage for global energy shipments.
The market clearly interpreted the development as a potential reduction in geopolitical risk.
Investors quickly moved back toward companies and sectors that had been pressured by fears of prolonged fighting. Technology stocks were among the biggest winners, helping propel the Nasdaq higher.
The gains came as Wall Street was already digesting a strong round of corporate earnings and looking for signs that the economy can continue expanding without another major inflation shock.
Amazon, for example, benefited from investor enthusiasm surrounding its earnings and artificial-intelligence business, with its market value moving above $3 trillion.
But despite Monday’s celebration, analysts are warning that investors should not declare victory just yet.
The situation involving Iran remains highly uncertain, and the diplomatic track could still break down. Any renewed military escalation could quickly reverse the market’s optimism, particularly if it threatens energy supplies or shipping through the Strait of Hormuz.
Vital Knowledge founder Adam Crisafulli offered a blunt warning about the latest rally:
“That said, ‘investors are keeping their enthusiasm in check as ‘we’ve been here before’ and it’s likely the conflict has further to go before reaching a resolution (if it ever does),’”
That caution is worth remembering.
Markets have repeatedly responded to developments in the Iran conflict, only to swing in the opposite direction when diplomatic hopes weaken. Traders are therefore watching Washington and Tehran closely for evidence that the latest pause represents something more durable than another temporary break in hostilities.
The oil market may be the biggest immediate indicator.
A sustained decline in crude prices could provide relief for consumers and businesses while taking some pressure off inflation expectations. Lower energy prices could also help airlines, transportation companies and other businesses that depend heavily on fuel.
Treasury markets also reflected the changing outlook. Yields moved lower as investors responded to falling oil prices and reduced geopolitical anxiety. That helped reinforce the broader risk-on mood sweeping through markets.
Still, Wall Street has another major issue waiting in the wings: the American labor market.
Investors are preparing for a busy week of economic data, culminating in Friday’s employment report. The numbers could have major implications for expectations surrounding Federal Reserve policy and the broader direction of the economy.
The key question is whether hiring remains strong enough to support economic growth without creating renewed inflation pressure.
For now, investors appear willing to focus on the positive.
The Dow closed at a fresh record, while the S&P 500 came within striking distance of its own all-time high and the Nasdaq extended its winning streak.
But the rally is being driven by a fragile assumption: that diplomacy can keep the Middle East from sliding back toward a wider conflict.
If that assumption holds, falling oil prices could become an important tailwind for the U.S. economy.
If it fails, Wall Street could discover just how quickly optimism can disappear.
For the moment, however, investors are betting that Trump’s decision to give diplomacy another chance may have bought the markets something they badly needed — breathing room.
