NASDAQ 100

The NASDAQ 100 tracks the 100 largest companies on the Nasdaq exchange, leaving out banks and other financial firms. Because the biggest names are tech and tech-adjacent giants, it is the market's go-to gauge of how investors feel about technology and growth.

It is weighted by company size, so a handful of mega-companies can swing the whole index. Forex traders watch it as a risk sentiment thermometer: a roaring Nasdaq usually means risk-on, while a sharp drop often sends money hiding in safe havens.