Index fund data spotlights Nvidia’s dominance over Apple in S&P 500 allocations

Holdings data tied to the S&P 500 is again underscoring how concentrated the market has become at the top end of large-cap performance. In a new look at index-fund positions, the leading exposure in the widely followed “biggest” S&P 500 index funds is now going to Nvidia rather than Apple, according to the report.

The change in the top spot first occurred in 2024, the post said, and the difference between the two stocks has widened since then. It also described the gap as running into “hundreds of billions” of dollars, reflecting how index construction can mechanically amplify the largest winners as investors continue to rely on passive funds.

The post further framed the concentration in terms of breadth within the funds. It said that a quarter of the biggest S&P 500 index fund’s exposure is held in five stocks, placing a small group of companies at the center of benchmark performance.

Apple, the S&P 500’s long-established mega-cap, remains one of the benchmark’s most prominent constituents. But the report’s comparison highlights that being a top name is not the same as being the top allocation, especially when the market rapidly reprices certain semiconductors and AI-related demand prospects.

Nvidia’s rise, as captured through index-fund ownership, is a reminder that passive vehicles do not just mirror investor sentiment, they also import it into the balance sheet of the public companies they hold. When a stock gains weight in an index, new inflows to index funds can translate into continued buying support, all else equal.

Sector context matters here because technology has been one of the primary drivers of performance dispersion inside the S&P 500. Apple is typically viewed as a consumer hardware and services platform, while Nvidia is more closely tied to the compute stack. That difference can show up quickly in index weights when investor expectations diverge.

The update does not provide the underlying methodology, the specific funds used for the comparison, or the exact holdings and dollar figures that produce the “hundreds of billions” framing. It also does not explain whether the reported figures reflect net buys, total market value, or a particular reporting date, leaving some mechanics unclear.

What to watch next is whether Apple’s index weight stabilizes relative to Nvidia, or whether the concentration described as reaching a quarter of the fund in five stocks continues to grow. Analysts will also likely look for additional disclosures or follow-up analysis that breaks down the time path of these holdings and how much is driven by price movement versus fund flows.