What Is OEF? iShares S&P 100 ETF
Last updated July 2026
Short answer
OEF is iShares S&P 100 ETF, an ETF that tracks a broad US large-cap equity index at a 0.20% expense ratio. OEF tracks a broad US large-cap equity index. At 0.20% it costs more than the typical large blend fund, nearer 0.15%. The distribution yield is about 0.88%. It has traded since 2000, so its record spans more than one full cycle. It is concentrated: the ten largest positions are about 51% of the fund, led by NVDA at 10.5%.
OEF is issued by iShares and tracks a broad US large-cap equity index. It charges a 0.20% expense ratio, holds approximately $20.0B in assets under management, yields about 0.88%, and launched in 2000.
What is OEF?
OEF is iShares S&P 100 ETF, an ETF that tracks a broad US large-cap equity index at a 0.20% expense ratio. OEF tracks a broad US large-cap equity index. At 0.20% it costs more than the typical large blend fund, nearer 0.15%. The distribution yield is about 0.88%. It has traded since 2000, so its record spans more than one full cycle. It is concentrated: the ten largest positions are about 51% of the fund, led by NVDA at 10.5%.
OEF is issued by iShares and tracks a broad US large-cap equity index, so a single ticker gives you the whole portfolio of underlying holdings weighted by the index's methodology rather than by any active stock-picking.
What does OEF hold?
OEF is weighted toward its largest constituents. As of August 2026, the top holdings are:
| Rank | Ticker | Company | % of OEF | |
|---|---|---|---|---|
| 1 | NVDA | NVIDIA Corp | 10.5% | |
| 2 | AAPL | Apple Inc | 9.2% | |
| 3 | MSFT | Microsoft Corp | 6.0% | |
| 4 | AMZN | Amazon.com Inc | 5.0% | |
| 5 | GOOGL | Alphabet Inc Class A | 4.5% | |
| 6 | AVGO | Broadcom Inc | 3.9% | |
| 7 | GOOG | Alphabet Inc Class C | 3.6% | |
| 8 | MU | Micron Technology Inc | 2.8% | |
| 9 | META | Meta Platforms Inc Class A | 2.7% | |
| 10 | TSLA | Tesla Inc | 2.6% |
The remaining holdings make up the balance of the fund, with weights tapering off below the top names. Because the index reconstitutes on a rolling basis, the roster stays current without active management. Each ticker above links to its individual stock guide in Walnut.
How do I invest in OEF?
There are three common ways to get OEF exposure. Buy shares (or fractional shares) of OEF directly at any major broker that lists it. Hold it as a core position and layer more concentrated ideas on top. Or build it into a thematic portfolio in Walnut, so OEF sits alongside other holdings that express the same thesis, with target weights you can rebalance toward. OEF trades like a stock during market hours, so you buy it the same way you would any listed share.
New to buying funds? See how to buy an ETF, step by step.
Is OEF a good buy?
Whether OEF is a good buy depends less on any single call and more on your time horizon and what you already hold: it tracks a broad US large-cap equity index, so the real question is whether you want that exposure in your mix and at what weight. We walk through valuation, concentration, and what would have to be true for it to outperform from here in is OEF a buy?
The bottom line on OEF
OEF gives you a broad US large-cap equity index exposure in one ticker at a 0.20% expense ratio. Most investors use it as a core holding and layer more concentrated thematic portfolios on top.
More on OEF
Whether OEF is worth buying today depends more on your time horizon and what you already hold than on any single call. We walk through valuation, concentration, and what would have to be true for it to outperform from here in is OEF a buy?
OEF yields 0.88% as of August 2026, paid by passing through the dividends of its underlying holdings. For the payout schedule, history, and how the distributions are taxed, see OEF dividend: yield and schedule.
New to funds like OEF? Start with what an ETF is, then how to buy an ETF, or browse the full guide to ETF investing.
Wondering how OEF fits the portfolio you already own? Walnut is an AI investing app that connects your brokerage read-only and answers questions like that about your actual holdings: overlap, concentration, and how each position tracks the S&P 500. Compare the best AI portfolio analyzers or see the best AI investing apps in 2026.
Investing in OEF with AI
Connect the broker you already use and ask Walnut's AI how OEF fits what you actually hold: what it overlaps with, what it leaves you exposed to, and how it has tracked the S&P 500. Read-only by default, and you approve anything before it reaches your broker.
FAQ
What is OEF's ticker symbol?
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OEF, iShares S&P 100 ETF. Issued by iShares; tracks a broad US large-cap equity index. Trades during US market hours, available at every major US brokerage.
What is OEF's expense ratio?
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0.20% as of August 2026.
What are OEF's top holdings?
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Top holdings as of August 2026: NVDA, AAPL, MSFT, AMZN, GOOGL and others. See the full holdings table above.
How can I invest in OEF through Walnut?
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Walnut isn't a broker. Connect a brokerage and Walnut sits on top to help you build and track thematic portfolios. OEF can be a constituent alongside individual stocks.
How do I compare OEF to similar ETFs?
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Put a few fields side by side: the expense ratio (fees compound over decades), the index or strategy it tracks, the top holdings and how much they overlap with what you already own, the dividend yield, and the AUM, liquidity, and bid-ask spread that affect trading costs. For index funds, tracking error (how closely it follows its index) and tax efficiency matter too. OEF's figures are above; the full method is in Walnut's guide on how to compare ETFs.
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Walnut is informational, not investment advice. Holdings weights and fund statistics on this page are approximations stamped to August 2026; verify current figures against iShares's fund page or your broker before investing.