RSP's $100B crossing makes equal weight a core allocation

RSP crossed $100 billion in assets this month, a milestone that has less to do with performance than with what advisors now expect from an S&P 500 fund. Invesco's equal-weight ETF gives each constituent roughly a 0.20% weight, a construction that has existed since April 24, 2003 but is only now drawing the scale to be considered a core holding rather than a tactical satellite.

The money has been moving for a while: VettaFi's director of research, Cinthia Murphy, told ETF Trends that RSP picked up $1.5 billion in net new money in July alone, and the fund is currently among the 15 most popular ETFs of 2026. August inflows carried total assets over the $100 billion threshold, against a backdrop where 2026 ETF flows are already upstaging 2025's record-breaking numbers, according to ETF Trends.

Performance is the easy explanation for the flows, and it is not a complete one: through Aug. 27, the S&P 500 Equal Weight Index was up 15.76% year to date while the cap-weighted S&P 500 was up 12.13%, a nearly four-point gap that is real but not built to win every market. The fund rebalances quarterly, trimming the names that have run up and shifting the proceeds into the names that have lagged—a discipline that is a headwind in a concentrated tech rally and a tailwind in a broadening one. Market leadership is broadening beyond technology and communication stocks into industrials, financials, and consumer names, a regime change that ETF Trends says gives equal weighting a structural advantage; Murphy said on CNBC that investors are turning their attention to the other 493 stocks as earnings growth broadens across the benchmark.

The $100 billion is a statement about concentration: the cap-weighted S&P 500 is effectively a bet that its largest members will keep generating outsized returns, while RSP is a bet on the index's breadth, with the top of the benchmark held to the same 0.20% weight as the bottom. That is a risk-management choice. If mega-cap earnings reaccelerate, RSP's rebalancing discipline becomes a drag and cap-weight retakes the lead. But the flows suggest that more investors are willing to give up the upside of concentration for protection from it.

The structure is what makes the milestone durable, and as this publication has reported, the same rules-based discipline shows up across the ETF shelf; GFLW's June rebalance halved Sterling Infrastructure's stake after a 114% rally because the index's free-cash-flow rules said a winner had become too large. RSP's quarterly rebalance is the original version of that idea, applied to the entire S&P 500: it does not forecast which sectors will lead; it resets exposure at regular intervals and lets the market decide what the fund owns.

Crossing $100 billion is also a distribution event, giving the fund a base of assets that makes it harder for advisors to ignore and likely encourages model allocations. Whether equal weight continues to outperform, as ETF Trends notes, depends on the relative performance of the S&P 500's largest companies versus the broader group of constituents; for now, the $100 billion is the evidence that the broader group has become the default allocation.