Stocks were range-bound for much of Monday's session, cruising towards what looked like an easy victory, but news that President Trump will announce his decision regarding the Iran nuclear deal on Tuesday prompted a wave of selling in the late afternoon. The market bounced back a bit following the initial reaction, but still finished off its highs of the day. The S&P 500 and the Dow settled with gains of 0.4% apiece, while the tech-heavy Nasdaq and the small-cap Russell 2000 ended with respective gains 0.8% and 0.9%. 

The energy sector led the broader market higher out of the gate, moving in tandem with crude oil prices, which hit their highest level in three-and-a-half years; the energy sector was up 2.4% at its highest mark of the day, while WTI crude futures were up 1.6% at $70.81/bbl. However, those gains were completely unraveled after President Trump tweeted that he'll be announcing his decision to either stay or pull out of the Iran nuclear deal at 2:00 PM ET on Tuesday. The president is expected to pull out of the deal -- thereby restoring sanctions on Iran, a top oil exporter -- but that's not for certain.

Energy eventually finished with a gain of 0.2%, closing near the center of the sector standings. The top-weighted technology sector (+0.8%) trailed energy in second place through much of the session and took over the top spot on the leaderboard after energy fell. Within the tech space, Apple (AAPL 185.16, +1.33, +0.7%) climbed for the sixth session in a row, settling at a new all-time high, and NVIDIA (NVDA 248.68, +9.62, +4.0%) soared after Bank of America/Merrill Lynch maintained its 'Buy' rating ahead of Thursday's earnings report.

The financials (+0.7%) and industrials (+0.7%) groups closed right behind technology at the top of the sector standings, while the other advancing sectors finished with gains between less than 0.1% and 0.4%. On the downside, the health care (-0.1%), consumer staples (-0.6%), utilities (-0.5%), and telecom services (-0.6%) sectors -- all of which are countercyclical groups -- settled in negative territory.

Elsewhere, U.S. Treasuries began the week on a modestly lower, but mostly quiet, note amid a lack of notable economic data; the yield on the benchmark 10-yr Treasury note advanced one basis point to 2.95%.

Monday's lone economic report -- the Consumer Credit report for March -- showed an increase of $11.7 billion (Briefing.com consensus $16.1 billion). The key takeaway from the report is that there was a decline in outstanding revolving credit for the second straight month, which reflects a propensity by consumers to pay down debt in a rising interest rate environment. That inclination helps explain why consumer spending growth was lackluster in the first quarter.

• Nasdaq Composite: +5.2% YTD
• Russell 2000: +2.8% YTD
• S&P 500: UNCH YTD
• Dow Jones Industrial Average: -1.5% YTD

Headlines provided by Briefing.com