Today we wanted to clear up a common misconception we often see on social media which is the idea that FNILX and FXAIX are the same. Many people comment things like “FNILX is just FXAIX with no fees,” which just isn’t true. While they are very similar, they are not identical. Let’s break down the key differences.
FNILX, offered by Fidelity, tracks Fidelity’s own proprietary large-cap index, while FXAIX tracks the legendary S&P 500. Though their short-term performance looks close, FNILX launched in 2018, while the S&P 500 has been around since 1957 and follows its own strict selection rules. Both target large-cap U.S. stocks, but they differ in how they choose and weight them. For example, NVIDIA makes up 7.75% of FXAIX but 7.59% of FNILX. FXAIX holds 507 total stocks, while FNILX holds 511. Even their 5-year average annual returns show a large difference: 17.62% for FXAIX and 17.42% for FNILX. If they were truly identical, these numbers would match exactly.
Yes, FNILX’s biggest selling point is its 0% expense ratio. But that advantage fades when you consider its lower dividend yield, slightly weaker long-term performance, and higher turnover rate, which creates more taxable events. Meanwhile, FXAIX’s 0.015% expense ratio remains one of the lowest among all true S&P 500 funds.
FNILX is a strong index fund and deserves credit. But it’s not the same as the king index fund: FXAIX. Good looks bad when compared to the very best.
Source: Fidelity & Yahoo Finance
Consider making a donation to the wizards today. Your support helps keep The Personal Finance Wizards, LLC running and allows us to continue creating valuable content for our audience. We make very little from our free, user generated content on social media so every donation (big or small) goes a long way. Thank you!
Check out the link on our page to learn more about the best investing course ever created. Also, be sure to read the disclaimer on our page.
© 2025 The Personal Finance Wizards, LLC