The Vanguard S&P 500 ETF (VOO) has become the first ETF in history to surpass $1 trillion in assets under management, a landmark milestone for passive investing.
A $1.7 billion inflow in a single session pushed VOO above the $1 trillion threshold, according to data compiled by Bloomberg, making it the only ETF ever to reach that level.
VOO has led all ETFs in net inflows in 2026, pulling in more than $69 billion since January, building on a record-breaking year in which the fund expanded its asset base by roughly $250 billion.
That explosive growth allowed VOO to overtake its long-time rival, the SPDR S&P 500 ETF Trust (SPY), and claim the title of the world’s largest exchange-traded fund.
A key driver of VOO’s dominance is its razor-thin 0.03% expense ratio, exactly one-third of the 0.09% fee charged by SPY, giving cost-conscious investors a clear reason to choose it.
Because both funds track the same index and deliver essentially identical exposure, the lower-cost option has drawn a steady stream of investors away from competing products over many years.
The milestone reflects a multi-decade structural shift away from active stock-pickers and toward low-cost, automated indexing strategies that now define much of modern portfolio management.
Global ETF assets reached $21.9 trillion at the end of April, compared to just $6.4 trillion in early 2020, according to ETFGI, underscoring the scale of the passive investing revolution.
Despite the commercial success, critics point to a growing risk: VOO’s market-cap-weighted structure means its ballooning assets are heavily concentrated in a small number of mega-cap technology firms, including Nvidia Corp., Apple Inc., and Microsoft Corp.
That concentration has pushed the S&P 500’s average price-to-earnings ratio to 27.4x, a level that many analysts consider richly valued given ongoing geopolitical conflicts, inflationary pressures, and recession concerns.
Tracking the broad market through low-cost index funds remains a sound long-term strategy, but the index itself is increasingly being driven by a narrow group of large technology companies.
VOO’s closest competitors, the iShares Core S&P 500 ETF (IVV) with roughly $859.5 billion in assets and SPY with approximately $784.63 billion, are both within striking distance of the trillion-dollar mark.
If current inflow trends hold, IVV and SPY could follow VOO past $1 trillion, potentially making the threshold a standard benchmark rather than a singular achievement within the ETF industry.
