What is the current BIL expected move?

As of Oct 14, 2026, State Street SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) has an expected move of 0.21% over the next 37 days, implying a one-standard-deviation price range of $91.34 to $91.72 from the current $91.53. The expected move is derived from at-the-money straddle pricing and represents the market consensus for a ±1σ price move.

What does the BIL 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 BIL 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.

State Street SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) 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 1-3 Month T-Bill ETF (BIL) operates in the Financial Services sector, specifically the Asset Management - Bonds industry, with a market capitalization near $47.00B, listed on AMEX, carrying a beta of 0.00 to the broader market. The State Street SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) is designed to closely mirror the price appreciation and income generation of the Bloomberg 1-3 Month U. public since 2007-05-30.

Snapshot as of Oct 14, 2026.

Spot Price: $91.53
Expected Move: 0.2%
Implied High: $91.72
Implied Low: $91.34
Front DTE: 37 days

As of Oct 14, 2026, State Street SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) has an expected move of 0.21%, a one-standard-deviation implied price range of roughly $91.34 to $91.72 from the current $91.53. 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.

BIL Strategy Sizing to the Expected Move

With State Street SPDR Bloomberg 1-3 Month T-Bill ETF pricing an expected move of 0.21% from $91.53, 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.

How to read the BIL implied-range chart

The shaded range below shows the one-standard-deviation implied price band at each listed expiration, derived from ATM implied volatility scaled to days-to-expiration. The front-tenor expected move is 0.21%, anchoring an implied range of approximately $91.34 to $91.72. Under lognormal assumptions, roughly 68% of outcomes fall inside that band; 95% fall inside ±2σ; 99.7% inside ±3σ. The empirical equity-return distribution has fatter tails than lognormal, so true tail-outcome frequency is moderately higher than these closed-form numbers suggest.

BIL expected move and event pricing

Expected move widens with √time: a 5% 30-day move corresponds to roughly a 2.5% 7.5-day move and a 10% 120-day move. BIL term-structure is in backwardation (slope -0.002), so near-dated tenors price in disproportionate vol - usually because of a known event in the front-month window. Combined with the 94.1% IV rank, the implied move is meaningfully wider than the typical BIL trailing range, so even premium-selling structures need wide wings to absorb the elevated regime.

Sizing BIL structures to the expected move

Iron condors with wings at ±1σ collect the modal-outcome premium; ±1.5σ widens probability of inside-range to ~87% but cuts collected premium roughly in half. Strangles do the inverse trade - they pay against the same lognormal distribution, profiting when realized exceeds implied. Calendar spreads bet on the slope of the term structure rather than the level. BIL put/call volume ratio currently at 0.58 indicates speculative call flow dominates - look for upside-skewed sentiment. The expected move is the inputs the chain is pricing, not a forecast - realized moves above or below are normal under any distribution.

Learn how expected move is reported and how to read the data →

Shaded band shows the ±1σ implied price range (~68% probability under lognormal assumptions) at each expiration; the center line marks current spot. Bands widen with longer DTE since volatility scales with √time.

Per-expiration expected move for BIL derived from ATM implied volatility at each listed expiration. Implied high/low bounds are computed as $91.53 × (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
Oct 16, 2026	2	3.7%	0.3%	$91.78	$91.28
Nov 20, 2026	37	0.7%	0.2%	$91.74	$91.32
Jan 15, 2027	93	0.5%	0.3%	$91.78	$91.28
Apr 16, 2027	184	1.6%	1.1%	$92.57	$90.49
Sep 17, 2027	338	456.2%	439.0%	$493.35	$-310.29

Frequently asked BIL expected move questions

What is the current BIL expected move?: As of Oct 14, 2026, State Street SPDR Bloomberg 1-3 Month T-Bill ETF (BIL) has an expected move of 0.21% over the next 37 days, implying a one-standard-deviation price range of $91.34 to $91.72 from the current $91.53. The expected move is derived from at-the-money straddle pricing and represents the market consensus for a ±1σ price move.
What does the BIL 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 BIL 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.