IBB vs SPDW: Holdings Overlap
iShares · 254 holdings · $9.3B · as of 2026-03-31
SPDWState Street® SPDR® Portfolio Developed World ex-US ETF
State Street (SPDR) · 2342 holdings · $40.5B · as of 2026-08-04
Holdings snapshots are 126 days apart (IBB: 2026-03-31, SPDW: 2026-08-04). 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 IBB and SPDW?
iShares Biotechnology ETF (IBB, by iShares) holds 254 positions; State Street® SPDR® Portfolio Developed World ex-US ETF (SPDW, by State Street (SPDR)) holds 2342. They have 8 holdings in common, and by portfolio weight the two funds are 0.1% identical. In practical terms the pair is essentially distinct, holding almost none of the same securities.
- Overlap by Weight
- 0.1%Sum of the smaller weight of each shared holding
- Shared Holdings
- 8IBB holds 254 · SPDW holds 2342
- Weight in Shared Holdings
- IBB 2%·SPDW 0%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 IBB
246 of 254 positions (98.1% of the fund) are not held by SPDW. Showing the top 30 by weight.
Sector Breakdown
| Sector | IBB | SPDW |
|---|---|---|
| Health Care | 91.0% | 6.3% |
| Financials | 0.0% | 21.9% |
| Industrials | 0.0% | 13.2% |
| Information Technology | 0.0% | 12.6% |
| Materials | 0.0% | 5.9% |
| Other Sectors | 0.0% | 21.5% |
| Unclassified | 8.9% | 17.3% |
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. “Unclassified” is weight we could not classify (9% of IBB, 18% of SPDW).
Performance
| Fund | 1M | YTD | 1Y | 3Y (ann.) | 5Y (ann.) | 10Y (ann.) | Yield |
|---|---|---|---|---|---|---|---|
| IBB | -0.3% | +17.3% | +51.0% | +16.4% | +3.1% | +7.4% | 0.21% |
| SPDW | +3.1% | +17.9% | +30.1% | +19.9% | +10.1% | +10.3% | 2.94% |
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 IBB vs SPDW →
Shared Holdings(8)
The top 8 shared positions account for 100% of the overlap, led by XENE, BNTX and URGN.
 XENEXenon Pharmaceuticals Inc COM | 0.43% | 0.02% | 0.02% |
|---|---|---|---|
 BNTXBioNTech SE, ADR | 0.66% | 0.02% | 0.02% |
 URGNUrogen Pharma Ltd COM ILS0.01 | 0.06% | 0.02% | 0.02% |
 ABCLAbCellera Biologics, Inc. | 0.07% | 0.01% | 0.01% |
 GRFSGrifols SA | 0.10% | 0.01% | 0.01% |
 IMCRImmunocore Holdings plc | 0.10% | 0.01% | 0.01% |
 AUPHAurinia Pharmaceuticals Inc COM | 0.16% | 0.00% | 0.00% |
 ZYMEZymeworks Inc COM | 0.16% | 0.00% | 0.00% |
Frequently Asked Questions
How much do IBB and SPDW overlap?
IBB and SPDW overlap by 0.1% of portfolio weight. They share 8 holdings (IBB holds 254 positions and SPDW holds 2342), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IBB and SPDW?
The two portfolios are 0.1% identical by weight. Owning both is genuine diversification: the funds hold almost none of the same securities.
What are the biggest shared holdings of IBB and SPDW?
The largest positions held by both funds are XENE, BNTX, URGN, ABCL and GRFS. Together the top 8 shared positions account for 100% of the total overlap.
What does IBB own that SPDW doesn't?
246 positions (98.1% of IBB) are unique to IBB, led by GILD, AMGN and VRTX. In the other direction, 2334 positions (98.5% of SPDW) are unique to SPDW.