By Sinéad Carew and Avinash P
Aug 21 (Reuters) - The main U.S. stock indexes closed higher on Friday but posted weekly losses as investors were rattled by fluctuating government bond yields and a lack of clarity on progress in the Middle East.
The S&P 500 and the tech-heavy Nasdaq snapped a three-week winning streak, while the Dow registered its second consecutive weekly loss.
Equity investors have been taking their cues from the direction of U.S. government bond yields in recent sessions as the prospect
of higher borrowing costs dampened risk appetite.
Stocks had closed lower on Thursday as bond yields rose while equities had advanced on Wednesday as bond yields fell. U.S. Treasury Secretary Scott Bessent said on Thursday that the government could further increase its Treasury repurchases after a surprise announcement on Wednesday that it would spend double the expected amount on bond buybacks.
"Markets are taking a bit of a breather. It's a pretty calm day," said Chris Zaccarelli, chief investment officer at Northlight Asset Management in Charlotte, North Carolina.
"We've had a bit of a seesaw week where we had some ups and downs around Treasury yields climbing and the intervention from Treasury Secretary Bessent."
Also helping to ease investor worries was Friday's economic data, which showed that the strongest growth in the U.S. services sector in nearly two years powered a sharp acceleration in overall business activity in August. This offset a slowing of growth in a manufacturing sector that is being restrained by reduced stock building and supply disruptions from the Iran war.
Earlier, UBS Global Wealth Management raised its year-end target for the S&P 500 to 8,100, citing a stronger earnings outlook and robust corporate profit growth.
Adding to inflation concerns, however, oil futures settled higher for a sixth straight day, after U.S. President Donald Trump threatened economic sanctions on Iran's trading partners, raising expectations of tighter supply. For the week, Brent futures gained 6.39% while U.S. crude rose 5.66%.
According to preliminary data, the S&P 500 gained 32.94 points, or 0.43%, to end at 7,674.10 points, while the Nasdaq Composite gained 112.20 points, or 0.43%, to 26,179.37. The Dow Jones Industrial Average rose 520.93 points, or 0.99%, to 53,280.14.
Among the S&P 500's 11 major industry sectors, most advanced on Friday, with materials outperforming, while utilities lagged the most during the session.
In individual stocks, Ross Stores rallied after the value retailer raised its annual profit forecasts and reported better-than-expected quarterly results.
Shares of retail investor platform Robinhood rallied sharply. Crypto exchange operator Coinbase Global and bitcoin-hoarder Strategy jumped as bitcoin advanced and touched its highest levels since mid-May.
In the week ahead, investor attention will turn to quarterly results from AI chip leader Nvidia and software companies such as Intuit, Salesforce and CrowdStrike .
Next week's data releases include July's Personal Consumption Expenditures price index, which is the U.S. Federal Reserve's preferred inflation gauge. Tame July readings for consumer and producer prices had knocked down bets of an imminent central bank rate hike.
Investors are also waiting for Fed Chair Kevin Warsh's speech at the Jackson Hole symposium at the end of next week.
(Reporting by Sinead Carew in New York; Additional reporting by Avinash P and Purvi Agarwal in Bengaluru; Editing by Pooja Desai and Matthew Lewis)
