The S&P 500 declined on Monday, as weakness in major technology stocks and rising U.S. Treasury yields overshadowed positive sentiment from progress in U.S.-Iran talks over the weekend.

The S&P 500 closed down 0.4%, dragged lower by mega-cap tech shares, with Alphabet Inc. (GOOGL) and Amazon.com (AMZN) among the leading decliners.

The tech-heavy Nasdaq 100 index fell 0.2%, while the Dow Jones Industrial Average gained 0.3%.

Regarding Alphabet, the departure of two high-profile AI researchers has unsettled investors, according to Adam Crisafulli, founder of Vital Knowledge.

SpaceX shares fell for a third consecutive session following the aerospace company's inaugural investment-grade bond offering.

This pullback has dampened bullish enthusiasm, noted Matt Maley, chief market strategist at Miller Tabak + Co., who also pointed to rising Treasury yields as a headwind for equities.

Oil prices fell after signs of progress in weekend talks between the U.S. and Iran reignited hopes that the conflict could be nearing an end.

Despite the market pullback, Wall Street strategists are growing more optimistic about U.S. stocks.

Strategists surveyed by Bloomberg have raised their year-end targets for the S&P 500, citing reduced disruptions from the war in Iran and improved corporate earnings prospects.

Chip stocks remained a bright spot within the tech sector, with the market awaiting earnings from Micron Technology (MU) on Wednesday.

U.S. Treasury yields moved higher as markets continued to prepare for Federal Reserve rate hikes; Bank of America Securities now expects a cumulative 75 basis points of hikes from the Fed this year.

Key economic data this week includes Personal Consumption Expenditures and GDP figures due on Thursday.

At the close, the S&P 500 was down 0.4% at 7,472.79.

The Dow Jones Industrial Average was up 0.3% at 51,712.71.

The Nasdaq Composite Index was down 1.3% at 26,166.6.

The Nasdaq 100 Index was down 0.2% at 30,347.08.

The Russell 2000 Index was up 0.8% at 3,004.404.