IBB vs IWP: Holdings Overlap
iShares · 254 holdings · $9.3B · as of 2026-03-31
IWPiShares Russell Mid-Cap Growth ETF
iShares · 277 holdings · $20.5B · as of 2026-03-31
How similar are IBB and IWP?
iShares Biotechnology ETF (IBB, by iShares) holds 254 positions; iShares Russell Mid-Cap Growth ETF (IWP, by iShares) holds 277. They have 16 holdings in common, and by portfolio weight the two funds are 6.1% identical. In practical terms the pair is lightly overlapping, with most of each portfolio distinct.
- Overlap by Weight
- 6.1%Sum of the smaller weight of each shared holding
- Shared Holdings
- 16IBB holds 254 · IWP holds 277
- Weight in Shared Holdings
- IBB 18%·IWP 6%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
238 of 254 positions (81.4% of the fund) are not held by IWP. Showing the top 30 by weight.
Only in IWP
261 of 277 positions (93.8% of the fund) are not held by IBB. Showing the top 30 by weight.
Sector Breakdown
| Sector | IBB | IWP |
|---|---|---|
| Health Care | 91.0% | 14.9% |
| Industrials | 0.0% | 24.4% |
| Consumer Discretionary | 0.0% | 21.2% |
| Information Technology | 0.0% | 15.6% |
| Financials | 0.0% | 8.5% |
| Other Sectors | 0.0% | 15.3% |
| Unclassified | 8.9% | 0.0% |
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, 0% of IWP).
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% |
| IWP | +1.5% | +5.4% | +3.1% | +14.6% | +5.1% | +12.1% | 0.34% |
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 IWP →
Shared Holdings(16)
The top 10 shared positions account for 93% of the overlap, led by ALNY, INSM and NTRA.
 ALNYAlnylam Pharmaceuticals, Inc. | 3.99% | 1.51% | 1.51% |
|---|---|---|---|
 INSMInsmed, Inc. | 3.20% | 1.15% | 1.15% |
 NTRANatera, Inc. | 2.41% | 0.95% | 0.95% |
 IONSIonis Pharmaceuticals, Inc. | 1.11% | 0.40% | 0.40% |
 NBIXNeurocrine Biosciences, Inc. | 1.18% | 0.39% | 0.39% |
 MEDPMedpace Holdings, Inc. | 1.00% | 0.39% | 0.39% |
 EXELExelixis, Inc. | 0.99% | 0.33% | 0.33% |
 HALOHalozyme Therapeutics, Inc. | 0.69% | 0.27% | 0.27% |
 TEMTempus AI, Inc., Class A | 0.43% | 0.16% | 0.16% |
 1JKApellis Pharmaceuticals, Inc. | 0.39% | 0.16% | 0.16% |
 INCYIncyte Corp. | 1.70% | 0.14% | 0.14% |
 SMMTSummit Therapeutics, Inc. | 0.19% | 0.08% | 0.08% |
 RAREUltragenyx Pharmaceutical, Inc. | 0.18% | 0.07% | 0.07% |
 SRPTSarepta Therapeutics, Inc. | 0.20% | 0.06% | 0.06% |
 CAICaris Life Sciences, Inc. | 0.20% | 0.03% | 0.03% |
 RGENRepligen Corp. | 0.58% | 0.03% | 0.03% |
Frequently Asked Questions
How much do IBB and IWP overlap?
IBB and IWP overlap by 6.1% of portfolio weight. They share 16 holdings (IBB holds 254 positions and IWP holds 277), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IBB and IWP?
The two portfolios are 6.1% identical by weight. Owning both is not redundant. Most of each portfolio is distinct, so the funds can serve different roles.
What are the biggest shared holdings of IBB and IWP?
The largest positions held by both funds are ALNY, INSM, NTRA, IONS and NBIX. Together the top 10 shared positions account for 93% of the total overlap.
What does IBB own that IWP doesn't?
238 positions (81.4% of IBB) are unique to IBB, led by GILD, AMGN and VRTX. In the other direction, 261 positions (93.8% of IWP) are unique to IWP.