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What margin means for 15-minute Bitcoin contracts, and how often each margin held
A gap of $60 can be safe or shaky depending on how fast the market is moving and how many minutes are left. Margin puts both on one scale.
The definition
Margin is the distance between price and the strike, divided by the typical movement still to come:
margin = gap in dollars ÷ (typical one-minute move × square root of minutes left)
The square root is there because price spreads out with the square root of time, not in a straight line. A margin of 1 means price is one typical move past the strike for the time that remains.
A worked example
The strike is 81,000 and price is 81,060, so the gap is $60. A typical one-minute move lately is $20, and 9 minutes are left. The typical move over the rest of the window is 20 × 3 = $60. The margin is 60 ÷ 60 = 1.0.
The same $60 gap with 4 minutes left gives a typical remaining move of 20 × 2 = $40 and a margin of 1.5. The dollars did not change, but the call is safer.
How often each margin held
This table comes from 6,465 settled windows over 90 days, using Kalshi's real strikes and real results and the Coinbase price. Each number is the share of times price finished on the same side of the strike it was on at that point in the window. Bands with fewer than 150 samples are left out of the study, and neighbouring bands can differ by a point or two from noise.
| Margin | 10 minutes left | 7 minutes left |
|---|---|---|
| 0.5 to 0.8 | about 75% | about 78% |
| 0.8 to 1.2 | about 81% | about 88% |
| 1.2 to 1.6 | about 90% | about 91% |
| 1.6 to 2.0 | about 89% | about 94% |
| 2.0 and up | about 97% | about 97% |
These are measured past rates, not predictions. A call that held 90% of the time still finished the other way about 1 time in 10.
What to take from it
- Under a margin of about 1, a side is leaning, not proven. Carry labels those spots Building or Wait.
- Around 1.2 to 1.6, similar spots held about nine times in ten in this data. That is where Carry starts to confirm a side.
- Past 2, spots held in the high nineties, but they are rarer.
- Margin depends on the typical move Carry measures, so a quiet market and a busy market get different dollar gaps for the same margin.