The Vanguard S&P 500 ETF is about to cross a line no exchange-traded fund has crossed before. VOO’s assets under management sit at roughly $980.7 billion, and with daily inflows averaging $1.25 billion, the math says the $1 trillion mark arrives within days.
To put that number in perspective, $1 trillion is larger than the GDP of all but about 16 countries. And it’s sitting inside a single fund that charges investors 0.03% annually, or about $3 for every $10,000 invested.
How VOO ate SPY’s lunch
For years, the SPDR S&P 500 ETF Trust (SPY) was the undisputed heavyweight champion of ETFs. It launched in 1993, pioneered the entire category, and held the crown for decades. Then VOO showed up and started doing essentially the same thing for less money.
VOO overtook SPY to become the largest ETF back in February 2025. The gap has only widened since. VOO now leads SPY by roughly $200 billion in total assets.
The weapon was simple: fees. SPY charges an expense ratio of about 0.09%, which sounds trivial until you remember that VOO charges 0.03%.
Inflows into VOO exceeded $100 billion in 2025 alone. Eric Balchunas, a well-known ETF analyst, has described this phenomenon as the “VOO and Chill” strategy.
Why this milestone matters beyond bragging rights
Todd Rosenbluth of TMX VettaFi called the potential $1 trillion mark “a tremendous milestone for the ETF industry.”
The S&P 500 itself has been a major tailwind. Technology and artificial intelligence stocks have driven strong performance in the index, giving investors exactly the kind of returns that make a “set it and forget it” strategy look brilliant.
What this means for investors
For anyone already holding VOO, the trillion-dollar milestone changes nothing about the underlying investment. You still own a slice of roughly 500 large-cap US companies, weighted by market capitalization, with heavy exposure to tech giants.
There’s a concentration risk worth noting. The S&P 500 has become increasingly top-heavy, with a handful of mega-cap technology companies representing an outsized share of the index. Buying VOO means buying that concentration, whether you intended to or not.