IBB vs IJK: Holdings Overlap
iShares · 254 holdings · $9.3B · as of 2026-03-31
IJKiShares S&P Mid-Cap 400 Growth ETF
iShares · 242 holdings · $11.0B · as of 2026-03-31
How similar are IBB and IJK?
iShares Biotechnology ETF (IBB, by iShares) holds 254 positions; iShares S&P Mid-Cap 400 Growth ETF (IJK, by iShares) holds 242. They have 12 holdings in common, and by portfolio weight the two funds are 6.8% identical. In practical terms the pair is lightly overlapping, with most of each portfolio distinct.
- Overlap by Weight
- 6.8%Sum of the smaller weight of each shared holding
- Shared Holdings
- 12IBB holds 254 · IJK holds 242
- Weight in Shared Holdings
- IBB 12%·IJK 7%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
242 of 254 positions (87.4% of the fund) are not held by IJK. Showing the top 30 by weight.
Sector Breakdown
| Sector | IBB | IJK |
|---|---|---|
| Health Care | 91.0% | 14.4% |
| Industrials | 0.0% | 31.3% |
| Information Technology | 0.0% | 17.3% |
| Consumer Discretionary | 0.0% | 10.2% |
| Financials | 0.0% | 7.2% |
| Other Sectors | 0.0% | 19.4% |
| 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 IJK).
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% |
| IJK | +3.1% | +21.4% | +27.9% | +15.9% | +8.4% | +11.3% | 0.52% |
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 IJK →
Shared Holdings(12)
The top 10 shared positions account for 95% of the overlap, led by UTHR, NBIX and EXEL.
 UTHRUnited Therapeutics Corp. | 2.30% | 1.57% | 1.57% |
|---|---|---|---|
 NBIXNeurocrine Biosciences, Inc. | 1.18% | 0.81% | 0.81% |
 EXELExelixis, Inc. | 0.99% | 0.68% | 0.68% |
 MEDPMedpace Holdings, Inc. | 1.00% | 0.66% | 0.66% |
 ILMNIllumina, Inc. | 1.68% | 0.62% | 0.62% |
 ARWRArrowhead Pharmaceuticals, Inc. | 0.75% | 0.54% | 0.54% |
 HALOHalozyme Therapeutics, Inc. | 0.69% | 0.47% | 0.47% |
 ROIVRoivant Sciences Ltd. | 1.24% | 0.44% | 0.44% |
 BMRNBioMarin Pharmaceutical, Inc. | 0.98% | 0.38% | 0.38% |
 CYTKCytokinetics, Inc. | 0.73% | 0.27% | 0.27% |
 RGENRepligen Corp. | 0.58% | 0.21% | 0.21% |
 BRKRBruker Corp. | 0.34% | 0.13% | 0.13% |
Frequently Asked Questions
How much do IBB and IJK overlap?
IBB and IJK overlap by 6.8% of portfolio weight. They share 12 holdings (IBB holds 254 positions and IJK holds 242), based on each fund's latest SEC-reported holdings.
Is it redundant to own both IBB and IJK?
The two portfolios are 6.8% 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 IJK?
The largest positions held by both funds are UTHR, NBIX, EXEL, MEDP and ILMN. Together the top 10 shared positions account for 95% of the total overlap.
What does IBB own that IJK doesn't?
242 positions (87.4% of IBB) are unique to IBB, led by GILD, AMGN and VRTX. In the other direction, 230 positions (93.1% of IJK) are unique to IJK.