NEW YORK — The Invesco S&P 500 Equal Weight ETF (RSP) is closing in on $100 billion in assets under management, a milestone that reflects a sustained shift in market leadership away from a handful of mega-cap names.

RSP allocates an equal 0.2 percent weight to each of the 500 companies in the S&P 500. That contrasts sharply with the market-capitalization weighted index, which gives greater influence to companies with larger market values.

The S&P 500 closed today at 7,438, up 1.7 percent. Performance varied widely among its largest components: Microsoft rose 15.5 percent to $451.10, while Meta Platforms fell 8.0 percent to $539.03.

For years, a concentrated group of mega-cap technology stocks drove a disproportionate share of S&P 500 returns, meaning the performance of market-cap weighted funds like the SPDR S&P 500 ETF Trust (SPY) depended heavily on a few dominant names. That dynamic has shifted. A wider array of companies across sectors now contribute to the index's gains, reducing reliance on a handful of technology giants.

RSP benefits directly from this environment. Its quarterly rebalancing forces it to sell outperforming stocks and buy underperforming ones, maintaining equal exposure across all 500 companies and capturing returns from a rotating set of market leaders.

Investors are allocating more capital to equal-weight strategies to diversify U.S. equity exposure and reduce single-stock risk. In a market-cap weighted index, the top 10 holdings can represent more than 25 percent of the fund.

Nvidia, up 2.6 percent to $195.04 today, illustrates that mega-caps continue to perform. But the relative outperformance of the equal-weight index points to broader participation in the current rally—more companies are contributing to gains, not just the largest ones.

Whether sustained breadth continues to drive inflows into RSP depends on whether mid-cap and smaller large-cap companies maintain their momentum. A reversion to concentrated mega-cap leadership would pressure the equal-weight strategy's relative performance.