Options implied-probability calculator
Risk-neutral model estimates from one public venue’s recorded forward and ATM implied volatility.
Reset to BTC forward and default expiry · Reset to ETH forward and default expiry. When changing coin or venue, choose “Default” to select its expiry nearest 30 days with usable ATM IV and at least five strikes; otherwise the nearest expiry. Reset links also reset the target to that forward.
BTC finish probabilities at expiry
Constant-volatility Black-76 / lognormal risk-neutral model estimates. These complementary probabilities sum to 100% before rounding.
Recorded model inputs
Underlying: BTC · Public venue: Bybit
Forward F: $81,019.50 · Target K: $81,019.50
ATM IV σ (annualized): 36.39% · Time to expiry: 32.4034 days (T = 0.08877644 years, 365-day year)
Exact expiry: 2026-11-27 08:00:00 UTC
Observed chain rows, UTC: oldest 2026-10-25 22:18:39 UTC; newest 2026-10-25 22:18:39 UTC. Forward and ATM IV use this venue and expiry only.
Model and limitations
d₂ = (ln(F/K) − ½σ²T) / (σ√T). Above-target probability = N(d₂); below-target probability = 1 − N(d₂), where N is the standard normal cumulative distribution. Option delta uses N(d₁) and is a different quantity. The target does not change the ATM IV input.
These are risk-neutral model estimates, not real-world forecast odds, the probability of touching the target, a price prediction or calibrated historical hit rates. The constant ATM-IV model omits volatility skew, fat tails and changing IV. It is not a fitted market probability distribution.
ATM IV interpolates marks between listed strikes bracketing the forward. Missing or zero exchange IV marks cannot establish ATM IV. Only current, unexpired public-venue rows are used: observations over 20 minutes old or more than one minute in the future are excluded. Open interest is not used, so incomplete OI does not exclude valid IV inputs.
Recorded exchange snapshots are shared for up to 30 seconds and freshness is checked on each calculation. No executable option premiums or quoted option costs are calculated. Not financial advice.