The Vanguard S&P 500 ETF (VOO) has officially become the first ETF in history to surpass $1 trillion in assets under management, marking a landmark moment for both Vanguard and the broader ETF industry.

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 (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 the fee difference may appear small, the lower cost has helped attract hundreds of billions of dollars into VOO over the past several years. The fund reportedly added roughly $250 billion in assets during 2025 alone, one of the largest annual asset-gathering performances ever recorded by an ETF.

The Rise of 'VOO and Chill'

VOO's growth has become so pronounced that the phrase "VOO and Chill" has entered investing vernacular, reflecting a simple buy-and-hold strategy centered on low-cost exposure to the S&P 500.

Notably, Bloomberg analyst Eric Balchunas used this term once again today, describing how boring investing can be beautiful.

"MILESTONE: $VOO has officially hit $1T in assets.. looks surreal on ETF go there. First ETF to ever to do this, an unbelievable feat (it was at $660b 12mo ago). VOO & Chill rules the country. And why not? It's a great frickin' deal."

The fund owns roughly 500 of the largest U.S. companies, with technology remaining its largest sector allocation. Holdings such as Nvidia Corp (NVDA), Apple, Inc (AAPL), Microsoft Corp (MSFT), Amazon.com, Inc (AMZN), etc., have benefited from the ongoing artificial intelligence boom, helping propel both the S&P 500 and VOO to new highs.

The ETF's success also highlights the growing concentration of investor capital in broad-market passive products. Critics argue that increasing flows into index funds may amplify the influence of mega-cap technology stocks, while supporters contend that low-cost diversification remains one of the most effective long-term investment approaches available.

Why the Trillion-Dollar Mark Matters

Crossing the $1 trillion threshold is more than a symbolic achievement.

The milestone underscores the dominance of passive investing, the continued shift from mutual funds to ETFs, and investors' preference for low-cost market exposure over stock picking. It also demonstrates the scale ETFs have reached since the industry's launch more than three decades ago.

For Vanguard, the achievement reinforces the firm's long-standing strategy of offering simple, low-cost investment products. For the ETF industry, it represents a defining moment that many analysts expect will be remembered as a turning point in the evolution of asset management.

With specialized ETFs tied to artificial intelligence, cryptocurrency, and leveraged trading continuing to grab headlines, VOO's historic achievement serves as a reminder that the industry's biggest winner remains a straightforward S&P 500 index fund charging just three basis points a year.