Initial optimism surrounding a potential compromise between Washington and Tehran quickly evaporated as both sides appear to remain far from an agreement. Oil prices, which initially trended lower on reports of an amended peace plan, reversed course after Axios reported that the United States was dissatisfied with the latest Iranian proposal. US officials also denied speculation regarding the easing of sanctions on Iranian oil as part of the discussions. Consequently, crude rebounded by approximately 1.7% to around $103 per barrel, providing support to the energy sector.

This pressure on oil did not, however, prevent a degree of market resilience beyond mega-cap names. Six of the eleven S&P 500 sectors finished up, with energy, communication services, financials and real estate showing strength. The S&P 500 Equal Weight Index even advanced about 0.5%, while the market-cap-weighted index remained in the red, signaling a rotation out of the behemoths and into the broader market.

The primary pressure stemmed from the technology space, with the SOX semiconductor index falling approximately 3%, extending Friday's correction of nearly 4%. Seagate Technology (-7%) tumbled following comments from its CEO indicating that the construction of new fabs would take too long to meet the surging demand for memory in the short term. Sandisk (-5%) and Micron (-6%) also retreated.

The weakness spread to several stocks recently associated with the artificial intelligence trade. Lumentum (-9%) was among the S&P 500's steepest decliners, while Vertiv (-8%) weighed on the industrial sector. Tesla (-3%) and Oracle (-3%) lost ground, and Nvidia (-1%) edged lower ahead of its earnings report. The sharp underperformance of the S&P 500 High Beta Index, which fell 1.7%, confirmed a reduction in exposure to the names that have recently seen the strongest outperformance.

A few stocks managed to resist the trend outside the tech core. Alphabet (flat) briefly touched a new all-time high, while ServiceNow (+4%) surged following a "buy" rating reinstatement by Bank of America, lifting Salesforce (+3%) in its wake.

In the utilities sector, NextEra Energy (-5%) declined following the announcement of an all-stock merger with Dominion Energy (+9%), which saw a significant rally. The transaction is set to create the world's largest regulated utility group, but the market primarily penalized the potential dilutive impact on the acquirer.

Focus now shifts to Nvidia's earnings, which are due out on Wednesday evening, which will serve as a major litmus test for the entire AI value chain. Simultaneously, investors will remain attentive to the evolution of negotiations between Washington and Tehran as traffic in the Strait of Hormuz remains blocked.