State Street SPDR S&P Biotech ETF (XBI) Expected Move
Expected move estimates the probable price range for a given period based on at-the-money options pricing. It reflects the market consensus for volatility over the selected timeframe.
State Street SPDR S&P Biotech ETF (XBI) operates in the Financial Services sector, specifically the Asset Management industry, with a market capitalization near $8.35B, listed on AMEX, carrying a beta of 1.09 to the broader market. The State Street SPDR S&P Biotech ETF seeks to provide investment results that, before fees and expenses, correspond generally to the total return performance of the S&P Biotechnology Select Industry Index (the "Index")Seeks to provide exposure to the Biotechnology segment of the S&P TMI, which comprises the following sub-industries: BiotechnologySeeks to track a modified equal weighted index which provides the potential for unconcentrated industry exposure across large, mid and small cap stocksAllows investors to take strategic or tactical positions at a more targeted level than traditional sector based investing public since 2006-02-06.
Snapshot as of May 15, 2026.
- Spot Price
- $130.88
- Expected Move
- 8.5%
- Implied High
- $141.95
- Implied Low
- $119.81
- Front DTE
- 28 days
As of May 15, 2026, State Street SPDR S&P Biotech ETF (XBI) has an expected move of 8.46%, a one-standard-deviation implied price range of roughly $119.81 to $141.95 from the current $130.88. Expected move is derived from at-the-money straddle pricing and represents the market's pricing of a ±1σ move. Roughly 68% of outcomes should fall within this range under lognormal assumptions, though empirical markets have fatter tails.
XBI Strategy Sizing to the Expected Move
With State Street SPDR S&P Biotech ETF pricing an expected move of 8.46% from $130.88, risk-defined strategies sized to the implied range structurally target the modal outcome distribution. Iron condors with wings at the ±1σ expected move boundaries collect premium against the ~68% probability that spot stays inside the range under lognormal assumptions; strangles set wider at ±1.5σ or ±2σ target the tails but pay smaller per-trade premium. Long-vol structures (long straddles, ratio backspreads) profit when realized move exceeds the implied move, the inverse trade: they bet against the lognormal assumption itself, capitalizing on the empirically fatter equity-return tails.
Learn how expected move is reported and how to read the data →
Per-expiration expected move for XBI derived from ATM implied volatility at each listed expiration. Implied high/low bounds are computed as $130.88 × (1 ± expected move %). One standard-deviation range under lognormal assumptions, roughly 68% of outcomes fall inside.
| Expiration | DTE | ATM IV | Expected Move | Implied High | Implied Low |
|---|---|---|---|---|---|
| May 22, 2026 | 7 | 30.3% | 4.2% | $136.37 | $125.39 |
| May 29, 2026 | 14 | 29.1% | 5.7% | $138.34 | $123.42 |
| Jun 5, 2026 | 21 | 29.8% | 7.1% | $140.24 | $121.52 |
| Jun 12, 2026 | 28 | 29.8% | 8.3% | $141.68 | $120.08 |
| Jun 18, 2026 | 34 | 29.0% | 8.9% | $142.46 | $119.30 |
| Jun 26, 2026 | 42 | 29.6% | 10.0% | $144.02 | $117.74 |
| Jul 17, 2026 | 63 | 29.3% | 12.2% | $146.81 | $114.95 |
| Aug 21, 2026 | 98 | 30.3% | 15.7% | $151.43 | $110.33 |
| Sep 18, 2026 | 126 | 30.6% | 18.0% | $154.41 | $107.35 |
| Dec 18, 2026 | 217 | 30.3% | 23.4% | $161.46 | $100.30 |
| Jan 15, 2027 | 245 | 30.2% | 24.7% | $163.26 | $98.50 |
| Dec 17, 2027 | 581 | 31.0% | 39.1% | $182.07 | $79.69 |
| Jan 21, 2028 | 616 | 30.9% | 40.1% | $183.42 | $78.34 |
Frequently asked XBI expected move questions
- What is the current XBI expected move?
- As of May 15, 2026, State Street SPDR S&P Biotech ETF (XBI) has an expected move of 8.46% over the next 28 days, implying a one-standard-deviation price range of $119.81 to $141.95 from the current $130.88. The expected move is derived from at-the-money straddle pricing and represents the market consensus for a ±1σ price move.
- What does the XBI expected move mean for traders?
- Roughly 68% of outcomes should fall within ±1 expected move and 95% within ±2 under lognormal assumptions, though equity returns have empirically fatter tails than log-normal predicts. Strategies sized to the expected move (iron condors at ±1σ, strangles at ±1.5σ) target the typical outcome distribution; strategies that profit from tail moves (long-vol structures, ratio backspreads) target the tails the lognormal model under-prices.
- How is XBI expected move calculated?
- The expected move displayed here is derived from at-the-money implied volatility scaled to the chosen tenor: expected move % is approximately ATM IV times sqrt(T / 365), where T is days to expiration. An equivalent straddle-based form: the ATM straddle (call + put at the same strike) is roughly sqrt(2/pi) times spot times IV times sqrt(T/365), so the implied one-standard-deviation move is approximately 1.25 times ATM straddle divided by spot. The two formulations agree once the sqrt(2/pi) constant is reconciled.