The milestone caps a remarkable growth run for the low-cost index fund, which has emerged as the preferred vehicle for investors seeking broad exposure to the U.S. stock market. VOO overtook the SPDR S&P 500 ETF Trust (NYSE:SPY) as the world’s largest ETF in early 2025 and has steadily widened its lead since then. The fund’s ascent has been fueled by strong market performance, massive investor inflows, and growing adoption of passive investment strategies among both retail and institutional investors.
Industry experts view the achievement as further evidence that low-cost ETFs have become the default building blocks of modern portfolios, replacing many traditional mutual funds as investors’ preferred investment vehicle.
VOO Vs. SPY: The Fee Advantage That Changed The ETF Industry
For decades, SPY was synonymous with ETFs, and a proxy for the S&P 500 Index. As the first U.S.-listed ETF, it dominated the category and held the title of the world’s largest ETF for more than 30 years.
VOO ultimately won investors over with a simple proposition: nearly identical exposure to the S&P 500 at a significantly lower cost.
Key Differences
VOO assets: More than $1 trillion
SPY assets: Approximately $775 billion
VOO expense ratio: 0.03%
SPY expense ratio: 0.09%
Index tracked: S&P 500 for both funds
While ...
