FXAIX tracks the S&P 500, mirroring the performance of large-cap US equities. It's a passive, low-cost fund ideal for exposure to the broader economy. Starting 2025, it will also use derivatives in its strategy, potentially enhancing returns or managing risks. The fund's ability to lend securities can generate additional income. Investors consider macro factors like GDP growth, interest rates, and market cycles when investing in FXAIX, as these impact the constituent companies of the S&P 500.