12 Best Fidelity Index Funds in 2026

Fidelity Investments offers a range of index funds, including a pioneering suite with zero expense ratios, alongside other popular and high-performing options with varying costs [1]. The funds track different market segments, from broad U.S. indexes to niche international and small-cap holdings [1]. In 2018, Fidelity became the first major broker to introduce index funds with no expense ratios, a move seen as a customer acquisition strategy [1]. These four 'ZERO' funds are only available to Fidelity account holders [1]. As of June 2026, the Fidelity ZERO Extended Market Index Fund (FZIPX) had a one-year return of 35.50%, while the ZERO International Index Fund (FZILX) returned 34.01% [1]. According to Investment Company Institute research, the average expense ratio for an index fund in 2025 was 0.05% [1]. Index funds are designed to replicate the performance of a specified basket of securities, such as a stock market index, and are widely advocated for their low cost and difficulty to outperform consistently [4]. Among Fidelity's other offerings, small-cap funds have shown strong recent performance, reflecting their focus on newer companies with high growth potential [1]. The Fidelity Emerging Markets Index Fund (FPADX) led all listed funds with a 59.25% one-year return, carrying an expense ratio of 0.075% [1]. The Fidelity Small Cap Index Fund (FSSNX) returned 43.56% with a 0.025% expense ratio [1]. The most popular funds by assets under management are the Fidelity 500 Index Fund (FXAIX) with $791.7 billion, the Fidelity Total Market Index Fund (FSKAX) with $131.7 billion, and the Fidelity International Index Fund (FSPSX) with $81.5 billion [1]. FXAIX and FSKAX both have expense ratios of 0.015% [1]. Fidelity is one of the world's largest asset managers, with $5.9 trillion in discretionary assets under management as of December 2024 [2]. Many of its index funds track well-known benchmarks; for instance, a large-cap fund like FXAIX would track an index similar to the Russell 1000, which represents about 93% of the total market capitalization of the Russell 3000 Index [3].