FANG stocks - Facebook, Apple, Netflix and Google - each slipped more than 1.4%, while the tech-heavy Nasdaq 100 index fell 1.8% to its lowest level since mid-May.
The benchmark S&P 500 declined 0.8% to 2,421.37 at 11:56 a.m. Eastern.
The market's reliance on its heavily-weighted tech leaders has been an issue before, most recently on June 9, when the Nasdaq 100 plunged 2.4% in a single day following negative news on Apple.
Investors are growing increasingly wary of the space as they rotate out of so-called growth stocks amid monetary policy tightening from the Federal Reserve.
Consumer stocks were another weak spot for the S&P 500, with both the discretionary and staples groups dropping at least 0.9%. In the grocery space, Blue Apron traded slightly higher after a disappointing IPO that saw the company cut its range by 40% the day before pricing.
Weakness in tech also put a damper on a rally in financial shares spurred by the announcement of more than $90 billion in share buybacks. Up as much as 2% in earlier trading, the the S&P 500 Financials Index is now up just 0.6%.