Diversification Pivot: Equal-Weight ETFs Outperform S&P 500 Amid Mega-Cap Slump

The structural concentration of the S&P 500 is creating a performance gap, with cap-weighted funds like the SPDR S&P 500 ETF Trust (SPY) struggling under the weight of its largest constituents. In 2026, SPY has declined approximately 3% year-to-date, reflecting a period where a handful of mega-cap tech names no longer drive the entire market upward. This has highlighted the risks of portfolios that are nominally diversified but effectively tethered to a few dominant stocks. The Invesco S&P 500 Equal Weight ETF (RSP) has capitalized on this shift, posting a 1% YTD gain and outperforming SPY by nearly 5 percentage points. By assigning equal weights to its roughly 500 holdings and rebalancing quarterly, RSP reduces tech exposure to 14%—down from over 30% in cap-weighted versions—while increasing weight in Industrials (16%) and Financials (15%). For those seeking mega-cap exposure without the concentration risk, the Invesco S&P 100 Equal Weight ETF (EQWL) offers a middle ground. While it has seen a -1% YTD return due to its focus on the 100 largest companies, it boasts a five-year return of 67%, outperforming both RSP and EUSA over that longer horizon. The current trend suggests a rotation toward market breadth. While equal-weight funds face higher turnover and slightly higher expense ratios—0.20% for RSP—they offer a systematic rebalancing discipline that protects against the volatility of a few oversized technology names.