BlackRock Is Tweaking the S&P 500 Formula With Its New ETFs. Should You Be a Buyer?

BlackRock has launched two new S&P 500-tracking ETFs, TOPC and XOEF, designed to address investor concerns over the index's increasing concentration, with its top three holdings now comprising over 20% of the index. However, the article suggests these new funds, which aim to cap or exclude megacap exposure, may be less optimal than traditional S&P 500 ETFs. This is due to their higher expense ratios (0.15-0.2% vs. 0.03% for standard S&P 500 ETFs) and the argument that the S&P 500's historical strong performance is inherently driven by its market-cap weighting, allowing 'mega-winners' to disproportionately contribute to overall returns.

Analysis

BlackRock has launched two ETFs, the iShares S&P 500 3% Capped ETF (TOPC) and the iShares S&P 500 ex Top 100 ETF (XOEF), to address rising concentration risk in the S&P 500, where the top three holdings—Nvidia, Microsoft, and Apple—now constitute over 20% of the index. These products offer alternatives for investors wary of this top-heaviness by capping individual stock weights or excluding the largest 100 companies entirely. However, these new funds present significant drawbacks compared to traditional market-cap-weighted ETFs like the Vanguard S&P 500 ETF (VOO). The primary disadvantages are their considerably higher expense ratios—0.15% for TOPC and 0.2% for XOEF, versus just 0.03% for VOO—and their lack of a performance track record. The core argument against these new structures is that the S&P 500's historical success, exemplified by VOO's 13.6% average annualized 10-year return, is directly attributable to its market-cap weighting, which allows 'mega-winners' to disproportionately drive index performance. A J.P. Morgan study supports this, indicating that a minority of top-performing stocks are responsible for most of the market's long-term gains.

Key Decisions for Investors

• Investors should consider that the significantly lower expense ratio of traditional S&P 500 ETFs, such as VOO at 0.03%, presents a compelling cost advantage over the new capped-weight alternatives like TOPC (0.15%) and XOEF (0.2%).
• Evaluate the strategic trade-off of new capped or ex-megacap ETFs, as their design intentionally limits exposure to the top-performing stocks that have historically been the primary drivers of the S&P 500's returns.
• For core equity exposure, maintaining positions in established, low-cost, market-cap-weighted index funds remains the recommended strategy, as their structure is proven to capture the full upside of market-leading companies over the long term.