AMD has reclaimed the top spot in the iShares Semiconductor ETF after a sharp surge in its share price, according to the fund’s holdings data. As of July 15, AMD accounted for 8.51% of the iShares Semiconductor ETF’s assets, narrowly ahead of Nvidia at 8.35%, while Micron Technology was close behind at 7.73%, underscoring how recent momentum is reshaping the fund’s internal ranking.
The shift matters because the ETF’s underlying index imposes weight caps at quarterly rebalances, meaning the largest positions don’t simply mirror company size. Instead, they reflect which semiconductor names have outperformed since the last reset—an important lens for investors tracking where the latest semiconductor rally has translated into portfolio weight.
Key takeaways
- Price move: AMD took the largest position in the iShares Semiconductor ETF at 8.51% as of July 15, ahead of Nvidia at 8.35%.
- Catalyst: The ordering change follows a significant run-up in AMD and Micron over the past year, with weights drifting between quarterly index rebalances.
- Index mechanics: The fund’s index caps its five largest stocks at 8% at each reset, limiting how dominant any single mega-cap can become.
- Implication: The ETF’s top holdings are tracking share-price momentum rather than static valuation leadership—so rankings can flip quickly.
What drove the shift in top holdings
The iShares Semiconductor ETF follows the NYSE Semiconductor Index, which holds the 30 largest U.S.-listed semiconductor companies and weights them by float-adjusted market capitalization, but with a key constraint. According to the ETF’s index methodology, the five largest stocks are capped at 8% of the index when weights are reset, while all other constituents are capped at 4%.
Because the cap is applied at reconstitution, holdings weights can move materially during the quarter as individual stock prices change. The result is that between rebalances, performance—not corporate scale—tends to determine which names sit closest to the top of the fund.
Based on the holdings snapshot dated July 15, AMD’s weight rose to become the fund’s largest position at 8.51%. Nvidia is second at 8.35%, and Micron Technology is third at 7.73%. Broadcom is listed fourth at 7.32%, with the top four together spanning just over one percentage point—an arrangement that increases the odds that a single session’s trading can reorder the leaderboard.
Momentum changes the leaderboard, but not the business backdrop
Micron’s stock has been one of the biggest movers in the broader group. The article said Micron shares have risen more than 600% over the past year, compared with about 22% for Nvidia and more than 200% for AMD. In a capped-weight ETF like this one, that kind of outperformance tends to quickly translate into higher portfolio weight until the next reset pins each of the five largest stocks to the cap.
The fund’s ranking shift also aligns with reported fundamentals cited in the article. Micron reported fiscal third-quarter 2026 revenue of $41.5 billion, up from $23.9 billion in the prior quarter and $9.3 billion in the year-ago period, with net income of $28.2 billion. The company also highlighted the demand for high-bandwidth memory used to support AI accelerators, including its newest generation shipping in high volume.
For AMD, the article pointed to first-quarter revenue growth of 38% year over year to $10.3 billion, with data center revenue up 57% to $5.8 billion as its Instinct graphics processing units ramped. Management guided for roughly $11.2 billion of revenue in the second quarter, implying continued acceleration.
Nvidia’s relative position in the ETF is also tied to performance across the semiconductors supply chain. The article said Nvidia’s fiscal first-quarter 2027 revenue rose 85% year over year to a record $81.6 billion, with data center revenue increasing 92% to $75.2 billion. In other words, the fund’s internal reshuffle appears less like evidence of a weakening Nvidia business and more like a broader broadening of market leadership across memory and alternate AI accelerator supply.
How the index cap can amplify “winners” during the quarter
Even though Nvidia is described as much larger by overall company valuation, the ETF’s design prevents the stock from simply dominating the fund. According to the index rules, Nvidia would otherwise exceed the 8% ceiling by far under pure market-cap weighting, but the methodology pins each of the five largest stocks at 8% at the time the weights are set.
Between those quarterly resets, however, weights drift with share prices. The article argues that the ETF’s top spot is therefore best understood as a reflection of relative gains since the last rebalance rather than as a direct ranking of which chipmaker is “bigger.” It also suggests investors should treat the top positions as dynamic: if a stock runs past the cap, it is effectively capped at 8% at the next reset, and the allocation “restarts” when the index reconstitutes.
What investors may watch next
With the fund’s index rebalancing quarterly, the next step for investors is the upcoming index reconstitution after the most recent weight reset period. Watch whether AMD, Nvidia, and Micron continue to lead on share-price momentum into the next rebalance, and pay attention to any read-through from upcoming earnings, especially for segments tied to AI memory demand and data center GPU activity.
