SPY ETF Explained: The World’s Most Important Index Fund

Nov 16, 2025 · 4 min read · Launched in 1993, SPY (SPDR S&P 500 ETF Trust) is the oldest, largest, and one of the most traded ETFs on the planet. It tracks the S&P 500 Index — the 500 largest public companies in the United States — and has become the benchmark for how “the mark...