Biotech · equal-weight · ETF deep dive
SPDR S&P Biotech ETF XBI
The high-beta, equal-weight way to own the whole biotech bench — hundreds of small- and mid-cap drug developers weighted almost equally, so a single takeout or trial win moves the fund, and no megacap pharma dominates it.
Price & momentum chart & stats through 2026-07-10
Data summary: last close $159.03 on 2026-07-10, 3% below the 52-week high of $164.28, 87% above the 52-week low of $85.16; trading above its 200-day average of $125.25. Trailing returns: YTD +31%, 1-year +80%, 3-year +95%, 5-year +16%.
What it holds
Top 10 holdings
| Holding | Ticker | Weight |
|---|---|---|
| Apogee Therapeutics | APOG | 1.5% |
| Moderna | MRNA | 1.4% |
| Kymera Therapeutics | KYMR | 1.3% |
| Viking Therapeutics | VK | 1.3% |
| Erasca | ERAS | 1.3% |
| Twist Bioscience | TWST | 1.3% |
| Oruka Therapeutics | ORKA | 1.2% |
| CG Oncology | CGON | 1.2% |
| Praxis Precision Medicines | PRAX | 1.2% |
| Dianthus Therapeutics | DNTH | 1.2% |
Top-10 ≈ 13% of the fund (157 holdings total). Positions as of 2026-07-13, from the issuer fact sheet (source). Holdings drift daily; weights are a snapshot, not live.
Sector mix live, FMP
- Healthcare99.4%
- Financial Services0.4%
- Cash & Others0.2%
What this fund is
XBI tracks the S&P Biotechnology Select Industry Index — a modified equal-weight index, not a cap-weighted one. It takes the biotech sub-industry names out of the broad S&P Total Market Index and weights them roughly equally (subject to float and liquidity caps), then resets that equal weighting every quarter.
That single design choice is the whole story. In a cap-weighted biotech fund like IBB, a few $100B names carry the fund. In XBI a ~$2B clinical-stage company gets roughly the same weight as a megacap. So XBI is really a bet on the breadth of the biotech bench — M&A premiums, trial readouts, and the small/mid-cap risk cycle — rather than on any one franchise.
The quarterly reset is a built-in discipline: it systematically trims what ran and adds to what fell, the opposite of a momentum fund. It also means XBI is structurally higher-beta and more volatile than cap-weighted peers.
The Synthos read
How the tracked themes this fund rides are reading right now — conviction-weighted net stance from independent expert voices in the Synthos knowledge base (management/officials laned out). Snapshot as of 2026-07-12.
| Tracked theme | Net stance (−100 to +100) | Recent drift | Reliability |
|---|---|---|---|
| GLP-1 / obesity / biotech The tracked biotech theme skews large-cap (Lilly/Novo, GLP-1). XBI is the small/mid-cap complement — read this as sentiment on the broad drug-development cycle, not on XBI's specific names. | up +100 Very Bullish | — 8 claims | Insufficient |
Reliability tiers: Full ≥ 25 claims in the current window, Provisional 10–24, Insufficient < 10 (read as directional only). Net stance is a rate-of-change signal about the theme, not a price target for this fund and not advice. Themes can be right while the fund’s structure works against you.
Cost & structure
Expense ratio 0.35% (issuer, cross-checks against FMP).
1940-Act open-end ETF (SPDR Series Trust), listed on NYSE Arca since 2006. Holdings are fully transparent and published daily.
The index rebalances quarterly (effective after the third Friday of March, June, September and December), when equal weights are reset.
Honest fit
The job it does
- Gives you the entire small/mid biotech field in one line, so you capture takeout premiums and trial pops without stock-picking.
- Deliberately avoids single-name dominance — no megacap can carry (or sink) the fund.
- Acts as a clean risk-on biotech expression: it tends to lead when rates fall and risk appetite returns.
What it does not do
- Is not a large-cap pharma bet — you will not get the megacaps that anchor IBB.
- Is not low-volatility — the small-cap, equal-weight tilt makes it high-beta and drawdown-prone.
- Will lag when a single megacap biotech rallies alone, because XBI barely holds it.
What would change this read (falsifiers)
- A durable rate up-cycle: long-duration, cash-burning biotechs de-rate hardest when discount rates rise.
- An M&A freeze (antitrust or capital-cost driven) removes the takeout-premium engine that equal-weight biotech relies on.
- If your actual thesis is one franchise (a specific GLP-1, a specific platform), XBI dilutes it across 150+ names — the wrong tool.