State Street SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) 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 Bloomberg 3-12 Month T-Bill ETF (BILS) operates in the Financial Services sector, specifically the Asset Management industry, with a market capitalization near $3.99B, listed on AMEX, carrying a beta of 0.02 to the broader market. The State Street SPDR Bloomberg 3-12 Month T-Bill ETF seeks to provide investment results that, before fees and expenses, correspond generally to the price and yield performance of the Bloomberg 3-12 Month U. public since 2020-10-07.

Snapshot as of May 15, 2026.

Spot Price

$99.31

Expected Move

1.4%

Implied High

$100.68

Implied Low

$97.94

Front DTE

34 days

As of May 15, 2026, State Street SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) has an expected move of 1.38%, a one-standard-deviation implied price range of roughly $97.94 to $100.68 from the current $99.31. 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.

BILS Strategy Sizing to the Expected Move

With State Street SPDR Bloomberg 3-12 Month T-Bill ETF pricing an expected move of 1.38% from $99.31, 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 BILS derived from ATM implied volatility at each listed expiration. Implied high/low bounds are computed as $99.31 × (1 ± expected move %). One standard-deviation range under lognormal assumptions, roughly 68% of outcomes fall inside.

Frequently asked BILS expected move questions

What is the current BILS expected move?

As of May 15, 2026, State Street SPDR Bloomberg 3-12 Month T-Bill ETF (BILS) has an expected move of 1.38% over the next 34 days, implying a one-standard-deviation price range of $97.94 to $100.68 from the current $99.31. The expected move is derived from at-the-money straddle pricing and represents the market consensus for a ±1σ price move.

What does the BILS 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 BILS 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.