IBB vs XBI: holdings overlap, shared companies and scores
As of September 11, 2026, IBB and XBI overlap 41.9% by weight. iShares Biotechnology ETF (IBB): U.S. biotechnology stocks. State Street SPDR S&P Biotech ETF (XBI): U.S. biotech industry stocks.
Updated September 11, 2026
How much do IBB and XBI overlap?
As of September 11, 2026, IBB and XBI overlap 41.9% by weight.
76% of IBB is already inside XBI.
86% of XBI is already inside IBB.
IBB holds 239 companies and XBI holds 145; 119 are in both.
Computed by ETF Copilot from both funds' holdings rather than quoted from a data provider, and rebuilt nightly.
How does ETF Copilot score IBB and XBI?
As of September 11, 2026, ETF Copilot scores IBB 3.1 out of 10 and XBI 2.7 out of 10.
They differ most on Risk: IBB 4.2 and XBI 1.4.
The five factor scores behind them are set out below, 0–10 and higher is better, ranked against every US equity ETF we track.
| Factor | IBB | XBI |
|---|---|---|
| Growth | 1.9 | 1.6 |
| Valuation | 3.5 | — |
| Risk | 4.2 | 1.4 |
| Quality | 3.4 | 2.5 |
| Return | 3.1 | 4.7 |
XBI is the cheaper of the two at 0.35% a year
As of September 11, 2026, IBB charges 0.44% a year, yields 0.46% and holds $10.7B in assets across 239 positions.
As of September 11, 2026, XBI charges 0.35% a year, yields 0.15% and holds $11.3B in assets across 145 positions.
| Measure | IBB | XBI |
|---|---|---|
| Expense ratio | 0.44% | 0.35% |
| Dividend yield | 0.46% | 0.15% |
| Assets under management | $10.7B | $11.3B |
| Holdings | 239 | 145 |
Expense ratio, dividend yield and assets under management are reported by the fund and refreshed daily. Every other figure on this page is computed by ETF Copilot.
Where IBB and XBI trade against their own history
IBB trades at 22.7 times earnings, against its own median of 21.5, and is more expensive than 60% of its own 114 monthly readings since 2017.
XBI trades at 23.3 times earnings, against its own median of 17.7, and is more expensive than 79% of its own 114 monthly readings since 2017.
What moved IBB and XBI this week
IBB fell 5.1% in the week to September 11, 2026. The holdings that moved it most were Amgen (−15.0%), Vertex Pharmaceuticals (−7.6%) and Regeneron Pharmaceuticals (−7.3%); Roivant Sciences (+18.6%) pushed the other way.
XBI fell 5.0% in the week to September 11, 2026. The holdings that moved it most were Dyne Therapeutics (−27.0%), Sellas Life Sciences (−15.7%) and Amgen (−15.0%); Roivant Sciences (+18.6%) pushed the other way.
What do IBB and XBI each hold?
What's inside IBB: AI 1%.
48% of IBB is its ten largest holdings.
16% of XBI is its ten largest holdings.
Compare with similar funds
Cite this
ETF Copilot, “IBB vs XBI holdings overlap and scores”, as of September 11, 2026.
https://etf-copilot.com/compare/ibb-vs-xbi
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