US stocks extended declines on Friday, putting benchmarks on track to snap a string of weekly gains as investors continued to fret about stretched valuations in the tech sector.

The S&P 500 Index fell 1.1% at 11:46 a.m. in New York, and is now trading below its 50-day moving average. The tech-heavy Nasdaq 100 Index dropped 1.9%, putting both gauges on track to end a three-week winning streak. Block Inc., Microchip Technology Inc. and Take-Two Interactive Software Inc. were some of the biggest decliners.