OEF vs SPY: Holdings Overlap
iShares · 101 holdings · $20.4B · as of 2026-03-31
SPYState Street® SPDR® S&P 500® ETF Trust
State Street (SPDR) · 504 holdings · $812.0B · as of 2026-08-06
Holdings snapshots are 128 days apart (OEF: 2026-03-31, SPY: 2026-08-06). Weights and index membership change between snapshots, so the true current overlap is typically higher than shown. For funds tracking the same index, the gap can be 5–15 points.
How similar are OEF and SPY?
iShares S&P 100 ETF (OEF, by iShares) holds 101 positions; State Street® SPDR® S&P 500® ETF Trust (SPY, by State Street (SPDR)) holds 504. They have 99 holdings in common, and by portfolio weight the two funds are 70.3% identical. In practical terms the pair is heavily overlapping, with largely the same stocks driving both funds.
- Overlap by Weight
- 70.3%Sum of the smaller weight of each shared holding
- Shared Holdings
- 99OEF holds 101 · SPY holds 504
- Weight in Shared Holdings
- OEF 98%·SPY 71%Share of each fund's weight in stocks both funds own
Based on each fund's latest official holdings. How is this calculated?
What makes each fund different
Only in OEF
2 of 101 positions (2.1% of the fund) are not held by SPY.
Only in SPY
405 of 504 positions (28.4% of the fund) are not held by OEF. Showing the top 30 by weight.
Sector Breakdown
| Sector | OEF | SPY |
|---|---|---|
| Information Technology | 38.9% | 37.6% |
| Communication Services | 13.5% | 9.7% |
| Financials | 11.2% | 12.3% |
| Consumer Discretionary | 10.2% | 9.3% |
| Health Care | 9.3% | 8.9% |
| Other Sectors | 16.7% | 22.1% |
Share of each fund's portfolio weight by GICS-style sector, compiled from issuer fund data and our own classification of the holdings, not the issuers' published sector charts.
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| OEF | +4.0% | +12.2% | +23.1% | +23.3% | +14.9% | +16.5% | 0.84% |
| SPY | +3.4% | +14.0% | +23.7% | +21.2% | +13.3% | +15.3% | 0.97% |
Total returns including dividends, from adjusted daily closes as of 2026-08-07. 3Y/5Y/10Y are annualized. Yield is trailing-12-month distributions over the last close. Past performance does not predict future results.
Project the growth of $10,000 in OEF vs SPY →
Shared Holdings(99)
The top 10 shared positions account for 54% of the overlap, led by NVDA, AAPL and MSFT.
 NVDANVIDIA Corp. COM | 10.50% | 8.00% | 8.00% |
|---|---|---|---|
 AAPLApple Inc. COM | 9.23% | 6.92% | 6.92% |
 MSFTMicrosoft Corp. COM | 6.81% | 5.60% | 5.60% |
 AMZNAmazon.com, Inc. COM | 5.04% | 4.02% | 4.02% |
 GOOGLAlphabet Inc. CAP STK CL A | 4.15% | 3.16% | 3.16% |
 AVGOBroadcom Inc COM | 3.63% | 3.00% | 3.00% |
 GOOGAlphabet Inc. CAP STK CL C | 3.32% | 2.54% | 2.54% |
 METAMeta Platforms, Inc., Class A | 3.10% | 1.95% | 1.95% |
 BRK-BBerkshire Hathaway, Inc., Class B | 2.18% | 1.45% | 1.45% |
 JPMJPMorgan Chase & Co. COM | 1.96% | 1.44% | 1.44% |
 LLYEli Lilly & Co. COM | 1.81% | 1.42% | 1.42% |
 TSLATesla Inc COM | 2.59% | 1.36% | 1.36% |
 MUMicron Technology Inc. COM | 0.94% | 1.50% | 0.94% |
 JNJJohnson & Johnson COM | 1.46% | 0.93% | 0.93% |
 VVisa, Inc., Class A | 1.26% | 0.93% | 0.93% |
 AMDAdvanced Micro Devices Inc. COM | 0.82% | 1.20% | 0.82% |
 WMTWalmart Inc COM | 1.35% | 0.74% | 0.74% |
 CSCOCisco Systems, Inc. COM | 0.76% | 0.72% | 0.72% |
 MAMasterCard Incorporated CL A | 1.01% | 0.70% | 0.70% |
 ABBVAbbVie Inc. COM | 0.95% | 0.65% | 0.65% |
 COSTCostco Wholesale Corporation COM | 1.10% | 0.63% | 0.63% |
 AMATApplied Materials Inc. COM | 0.67% | 0.63% | 0.63% |
 BACBank of America Corp. COM | 0.80% | 0.62% | 0.62% |
 CATCaterpillar Inc COM | 0.82% | 0.59% | 0.59% |
 GEGE Aerospace COM NEW | 0.74% | 0.59% | 0.59% |
Frequently Asked Questions
How much do OEF and SPY overlap?
OEF and SPY overlap by 70.3% of portfolio weight. They share 99 holdings (OEF holds 101 positions and SPY holds 504), based on each fund's latest SEC-reported holdings.
Is it redundant to own both OEF and SPY?
The two portfolios are 70.3% identical by weight. Owning both mostly doubles down on the shared core rather than diversifying: the same large positions drive both funds.
What are the biggest shared holdings of OEF and SPY?
The largest positions held by both funds are NVDA, AAPL, MSFT, AMZN and GOOGL. Together the top 10 shared positions account for 54% of the total overlap.
What does OEF own that SPY doesn't?
2 positions (2.1% of OEF) are unique to OEF, led by XOM and HON. In the other direction, 405 positions (28.4% of SPY) are unique to SPY.