The Nasdaq-100 fell broadly on Monday, with only one of the index's components in positive territory amid a sharp selloff driven by weakness in Facebook. The index NDX, -2.21% lost 2.6% in its biggest one-day drop since Feb. 8. Of the Nasdaq 100's components, which is dominated by large-capitalization technology and internet stocks, only Ross Stores Inc. ROST, +0.38% was higher on the day, up 0.2%. Facebook was the biggest decliner by far, shedding 6.3% and on track for its worst session in years. The stock came under heavy selling pressure over how it manages third-party access to its users' information, after saying a firm with ties to the 2016 Trump campaign improperly kept member data for years despite saying it had destroyed those records. Among other major drags to the index, Apple Inc. AAPL, -1.53% fell 1.9%, Amazon.com Inc. AMZN, -1.70% was down 2.4% and Alphabet Inc. GOOGL, -3.03% the parent company of Google, fell 3.7%. The Dow Jones Industrial Average DJIA, -1.35% fell 1.6% on Monday, and all 30 of its components were lower. The S&P 500 SPX, -1.42% was down 1.7%; all 11 primary S&P 500 sectors were in negative territory. The overall Nasdaq Composite Index COMP, -1.84% lost 2.3%.