- All of the 65 components of the S&P 500 Information Technology Index fell on Wednesday.
- The five most valuable companies — Alphabet, Amazon, Apple, Facebook and Microsoft — fell more than 4 percent each.
Technology stocks got clobbered on Wednesday, suffering their worst day in more than seven years, as concerns over rising interest rates punished the overall market, particularly shares of companies that have been the best performers.
The S&P 500 Information Technology Index closed at $1,220.62, down 4.8 percent, marking the biggest decline since August 18, 2011, when the index dropped 5.3 percent. All 65 members of the index fell. The broader S&P 500 dropped by 3.3 percent and the Dow Jones Industrial Average tumbled 3.2 percent.
The tech sector includes the largest companies by market cap in the U.S. and those that have been the biggest contributors to the extended rally. Shares of Apple, Microsoft and Amazon are up sharply for the year as investors bet they will continue to deliver strong earnings growth and take market share.
However, the same names have been susceptible to steep declines during periods of heavy selling as investors rotate into safer investments like bonds. Microsoft fell 5.4 percent, and Apple dropped 4.6 percent. Amazon, which is not a constituent of the S&P tech index, fell 6.2 percent, and Alphabet declined 4.6 percent.
The worst tech performers today are some of the year's best performers. AMD, which has climbed almost 150 percent in 2018, fell 8.2 percent on Wednesday, the biggest loser in the index. Intuit, Salesforce and Nvidia each dropped more than 7 percent, and are still up over 25 percent for the year.
— CNBC's Ari Levy contributed to this report.