Best Index Funds To Buy 2025. The fidelity zero large cap index (fnilx) is one of the best index funds tracking the s&p 500. If you're evaluating mutual funds for your investment portfolio or retirement account, this list highlights the best index fund to consider now, based on it having.

Find out which index funds tracking the s&p 500 have the lowest fees, highest assets under management, and most closely track the market. Check out these nine index funds that can help you achieve it.