5 Unique Passive ETF Ways of Owning the S&P 500

The Vanguard S&P 500 ETF (VOO) has experienced unprecedented asset growth in 2025, attracting $65 billion in net new assets, surpassing its record-breaking $116 billion inflow in 2024 and becoming the largest ETF at $608 billion. While VOO's ultra-low cost and Vanguard's brand are key drivers, the article highlights five alternative S&P 500 ETF strategies, including equal-weighted (RSP), historically-weighted (DSPY), revenue-weighted (RWL), and a defensive approach (GMMA), offering varied exposures and risk profiles compared to traditional market-cap-weighted ETFs like SPDR S&P 500 ETF Trust (SPY).

Analysis

The Vanguard S&P 500 ETF (VOO) is demonstrating remarkable asset accumulation, having attracted $65 billion in net new assets year-to-date through May 21, 2025, building on a record $116 billion inflow in 2024, and solidifying its position as the market's largest ETF with $608 billion in assets. This surge, occurring amidst market turbulence and valuation concerns, underscores strong investor appetite for U.S. market exposure, likely driven by VOO's ultra-low expense ratio of 3 basis points and Vanguard's brand strength. While the SPDR S&P 500 ETF Trust (SPY), with approximately $600 billion in assets and a 0.0945% expense ratio, remains a highly liquid benchmark, particularly for trading (evidenced by a single-day trading volume exceeding $100 billion), VOO's growth highlights a trend towards cost efficiency. Beyond these market-cap giants, the ETF landscape offers diverse S&P 500 exposures: the Invesco S&P 500 Equal Weight ETF (RSP) mitigates concentration by equally weighting constituents, resulting in a lower technology sector allocation (approximately 14% versus SPY's 30%) and a tilt towards smaller-cap names within the index. The Tema S&P 500 Historical Weight ETF (DSPY) offers a novel approach by assigning weights based on trailing 35-year averages for each stock's position, aiming to reduce top-heaviness, with its current top holding at 3.6% of the portfolio. Alternatively, the Invesco S&P 500 Revenue ETF (RWL) weights stocks by revenue, capping individual holdings at 5%, leading to a value tilt with top holdings like Walmart and Amazon, and a technology sector exposure of only 11%. For tactical management, the newly launched GammaRoad Market Navigation ETF (GMMA) dynamically shifts between S&P 500 exposure (potentially up to 125% leveraged) and T-bills based on proprietary risk indicators; it is currently defensively positioned with two-thirds in T-bills and one-third in the S&P 500, a shift from a 100% T-bill allocation the prior week.