State Street SPDR S&P 500 ETF

About State Street SPDR S&P 500 ETF

SPY is an exchange-traded fund structured as a unit investment trust that seeks to track the S&P 500 index, a benchmark of roughly 500 US large-cap securities selected by S&P Dow Jones Indices' index committee. Launched in 1993, it was the first US-listed ETF and is sponsored by State Street Global Advisors under the SPDR brand. The fund holds the index constituents in proportion to their index weights and trades intraday on exchanges like a stock.

Why it matters

SPY is widely cited as the largest ETF by assets under management and consistently ranks among the most heavily traded securities in US markets, giving it deep liquidity and tight spreads. Because it tracks the S&P 500, it functions as a core building block for US large-cap equity exposure and a common reference point for gauging broad market sentiment. Its scale and first-mover status make it a benchmark against which other index ETFs and asset managers are often compared.

How we research SPY

Fundamentals like the ones above feed our fundamental screen — EPS acceleration, ROE and momentum∧quality — the one research class that survives walk-forward in our testing. We don’t issue price targets or buy/sell calls: see /edge for how rigorously (and how rarely) anything passes. This page is market data and research, not investment advice.