Are Kalshi's 15-minute Bitcoin markets rigged? What the second-by-second data shows
It's the most common complaint about Kalshi's 15-minute Bitcoin markets: a side sits at 90¢ with two minutes left and still loses, and it feels rigged. What actually happens in those last minutes is in the data, second by second.
What a late flip is
Each market asks whether Bitcoin finishes the 15 minutes above the strike. A price of 90¢ means traders put about a 90% chance on it. One market in ten priced like that is supposed to lose, and with 96 markets a day, that is several a day: each one a trader who was "winning" until the end.
Why the last minute turns: the average
The result isn't Bitcoin's last price. It is the average of the official index over the final 60 seconds, against the strike. A price chart can sit above the strike at the close while the average of the minute sits below it - when Bitcoin spent the first part of the minute lower, or dropped hard in it. Every second of the final minute is locked into the average for good, which is why the side ahead on the chart and the side ahead on the average can differ. How the settlement works, with a worked example.
Checking the settlements ourselves
SettleMath reads the official index (CF Benchmarks' BRTI) every second and, after every market, averages its final 60 seconds itself and compares that with the official settlement value. After every market its final-minute average, as read, is checked against the official value: it has matched to the cent in 91 of 91 markets so far (the record is on the Accuracy page). In other words, the settlement is the rule applied to the index as published: what decides a late flip is where the index's average landed, not a change after the fact.
That doesn't say why the index moved the way it did in a given minute; it says the result followed it. The Live page shows every second of it, and each market's recap stays in the strip under the chart for about two hours.
The latest last-minute flips
Markets where the side priced at 75¢ or more with three, two or one minutes left ended up losing, and photo finishes that settled within $10 of the strike, as they happened:
| Market (15 minutes from) | What it looked like | Settled | From the strike |
|---|---|---|---|
| Nov 3, 1:45 PM CT | Down was 97¢ with 3:00 left | Up | $25.42 |
| Nov 3, 1:30 PM CT | Photo finish | Down | $7.25 |
| Nov 3, 11:30 AM CT | Up was 76¢ with 3:00 left | Down | $13.09 |
| Nov 3, 10:30 AM CT | Up was 88¢ with 3:00 left | Down | $23.57 |
| Nov 3, 8:15 AM CT | Up was 76¢ with 3:00 left | Down | $86.94 |
| Nov 3, 6:45 AM CT | Photo finish | Up | $2.59 |
| Nov 3, 5:45 AM CT | Photo finish | Down | $2.75 |
| Nov 3, 4:30 AM CT | Down was 76¢ with 3:00 left | Up | $11.98 |
| Nov 3, 4:15 AM CT | Down was 84¢ with 3:00 left | Up | $30.05 |
| Nov 3, 1:45 AM CT | Up was 76¢ with 3:00 left | Down | $15.74 |
See it live
The Live page shows every window as it happens: the model next to the market's price, the final minute's average as it locks in, and where the settlement is expected to land. The free view runs 60 seconds behind; Pro is live, weekly or monthly, cancel anytime (Pricing). Information, not advice.
More guides
- Are Kalshi's 15-minute Bitcoin markets rigged? What the second-by-second data shows
- How Kalshi's 15-minute Bitcoin market settles
- A Kalshi 15-minute Bitcoin bot, every trade public
- Kalshi 15-minute Bitcoin: what 90¢ with 2 minutes left has meant
- Why Kalshi's 15-minute Bitcoin markets can be too close to call