The NASDAQ-100 is widely followed as a measure mainly of the big tech and social media stocks that make up the index.

The tech-heavy Nasdaq 100 is the best performer but more risk-averse investors may prefer the more broadly diversified S&P 500.

It's often the case that U.S. traders treat an overnight sell-off in stock-index futures as an opportunity rather than a warning. So the next few hours, as the East coast wakes, up will be instructive ...

It printed an intraday low of 20,538 before it rebounded and closed at 20,784 at the end of the US session on Monday. The Nasdaq 100 has declined by 6% from its current all-time high level on 16 ...