The NASDAQ-100 is a stock market index that includes 100 of the largest non-financial companies listed on the NASDAQ stock exchange. It represents a diverse range of industries, including technology, consumer goods, and healthcare, making it a key indicator of the performance of the U.S. economy. Investors often use the NASDAQ-100 to gauge market trends and make investment decisions. Some well-known companies in this index include Apple, Amazon, and Microsoft. The index is weighted by market capitalization, meaning larger companies have a greater influence on its overall performance.