The major averages finished Monday broadly lower after a volatile session shaped by sharp swings in crude oil, elevated Treasury yields, and shifting headlines surrounding U.S.-Iran negotiations. The S&P 500 (-0.8%), Nasdaq Composite (-0.9%), and DJIA (-0.7%) ended near their late-session lows, though still above the worst levels reached during the morning.

Oil and interest rates provided the primary macro headwinds. WTI crude surged more than 3.0% to above $95 per barrel during the morning after President Trump rejected Iran's ceasefire proposal, while the 10-year note yield climbed as high as 5.26%. Those moves fueled broad selling that briefly pushed losses in the major averages toward or beyond 1.0%.

The tone improved considerably around midday as a series of headlines suggested that diplomatic channels remain open despite substantial differences between the U.S. and Iran. President Trump was reported by CNN to be open to sanctions relief in exchange for progress toward a nuclear deal, while Alhadath reported that Iran had agreed to halt uranium enrichment in exchange for easing U.S. sanctions. Other reports indicated that talks between the two sides are expected to continue this week. Those developments prompted a sharp reversal in crude oil, although uncertainty surrounding negotiations remained elevated.

A later Bloomberg report indicated that Iranian officials are pessimistic about reaching an agreement to end the war and reopen the Strait of Hormuz before the midterms. WTI ultimately settled just $0.27 higher (+0.3%) at $92.44 per barrel, far below its morning high.

Despite the intraday recovery, selling remained relatively broad into the close, with cyclical and growth-oriented areas accounting for much of the weakness. The communication services (-1.7%), consumer discretionary (-1.6%), financials (-1.1%), and industrials (-1.0%) sectors were among the largest laggards. Mega-cap stocks also remained under pressure, leaving the Vanguard Mega Cap Growth ETF down 0.9%, with Meta Platforms (META 715.62, -36.04, -4.79%) a particular laggard back after last week's double-digit advance.

Semiconductor stocks were another source of weakness, with the PHLX Semiconductor Index falling 1.6%. NVIDIA (NVDA 228.86, +3.79, +1.68%) remained a notable exception after increasing its share repurchase authorization by $150 billion to $235 billion and launching its Open Agent Safety Platform, helping the information technology sector (-0.7%) hold up better than several other growth-oriented areas.

Defensive-oriented stocks provided relative support. The consumer staples (+0.4%) and health care (+0.3%) sectors finished higher, while the energy sector (+0.2%) eked out a gain after surrendering much of its earlier advance as crude oil retreated.

Weakness also extended beyond the largest companies, with the Russell 2000 and S&P Mid Cap 400 both falling 0.7%.

There were several notable stock-specific moves outside the broader market narrative. MongoDB (MDB 334.68, -75.76, -18.46%) plunged after President and CEO Chirantan "CJ" Desai stepped down effective immediately to take a senior role at Meta Platforms, marking the company's second CEO transition in less than a year just ahead of its September 29 Investor Day. Former CEO Dev Ittycheria was named interim president and CEO as the company begins an external search, while MDB reaffirmed its Q3 and FY27 guidance.

NIKE (NKE 36.37, +0.62, +1.73%), meanwhile, displayed notable relative strength ahead of its fiscal Q1 report Thursday afternoon. The gain provided a reprieve from a difficult year for the stock, which remains down roughly 43% year-to-date amid an uneven turnaround marked by weakness in Greater China, discounting, competitive pressures, and questions surrounding the company's product pipeline and direct-to-consumer strategy.

Ultimately, the market was unable to sustain its midday recovery as elevated Treasury yields and lingering uncertainty surrounding the U.S.-Iran conflict kept pressure on equities. The sharp reversal in crude oil removed one of the morning's biggest headwinds, but weakness across cyclical stocks, mega-cap names, and semiconductors left the major averages with sizable losses at the close.

U.S. Treasuries had a rough start to the week, pinched at first by rising oil prices and then languishing on the back of ongoing secular issues that include stubbornly high inflation and increased debt issuance to cover a large budget deficit. Notably, Treasuries didn't recover much ground after oil prices scaled lower amid reports that the U.S. and Iran might be making progress toward a deal. The 2-year note yield settled up eight basis points to 4.93%, and the 10-year note yield settled up nine basis points to 4.25%. 

There was no economic data of note today.

• Nasdaq Composite: +15.4% YTD
• Russell 2000: +13.5% YTD
• S&P 500: +12.2% YTD
• S&P Mid Cap 400: +9.6% YTD
• DJIA: +7.1% YTD