US Markets Break Three-Week Winning Streak with Eyes on Monday's Open

US markets ended trading on Friday, August 21, on a daily gain but suffered a weekly loss that broke a three-consecutive-week winning streak; as the S&P 500 index rose 0.43% to close at 7,674.37 points, though it lost 1.4% on a weekly basis and continues to trade 1.6% away from its record high set on August 13.

Other major indices recorded similar performance; the Dow Jones rose 0.98% to close at 53,277 points, the Nasdaq Composite climbed 0.43% to 26,180 points, while the small-cap Russell 2000 jumped 0.85%. Futures for Monday's session point to a potentially positive start with gains ranging between 0.30% and 0.46% as markets assess the implications of Treasury Secretary Bessent's conference regarding Iran sanctions.

On the sector level, construction materials and healthcare led Friday's gains; elevated gold prices pushed mining shares higher, while the result of Moderna's Phase 3 clinical trial for its cancer vaccine—which surged 17%—lifted sentiment across the entire biotechnology sector. Conversely, technology declined due to investor concern over potential interest rate hikes and Warsh's hawkish comments, while the energy sector took a break for profit-taking following its weekly rally.

Artificial intelligence stocks remain the dominant story in the tech sector but are the most vulnerable to any shock in bond yields—which is precisely what makes Warsh's speech at Jackson Hole next Friday the single most critical determinant of tech stock performance in the coming weeks.

What do these terms mean?

S&P 500: An index comprising the 500 largest publicly traded US companies, considered the most comprehensive gauge of US stock market performance, followed by investors worldwide as a primary reference.

Moving Average (MA): The average price of an asset over a specific period of time (50 days or 200 days). Analysts use it to identify the general trend—staying above it is considered a sign of market health.

Futures: Trading contracts that allow investors to bet on index prices before the exchange opens, serving as a leading indicator for market direction at the open.