Why the final seconds can be too close to call
Some windows end a few dollars from the strike. In those, the result depends on an index no public tool can show, and the honest answer in the last seconds is: too close to call.
Why a public price can't always call it
The official value is an index calculated from several exchanges' order books, merged into one, every second. Its data needs a license, so a public tool uses its own price: SettleMath averages three of the exchanges in the index. The two track each other closely, but not to the cent, so a window that ends within a few dollars of the strike can go either way whatever our price says.
How often it happens
Over the last 7 days, our final-minute average landed within $12.19 of the official value in 95% of windows - the "too close to call" band - and the official value finished within that distance of the strike in 78 of 664 windows (12%). The model's own allowance for this error is $7.42 (σe, root-mean-square). The whole record is on the Accuracy page.
What the Live page does about it
When the final minute's average is within that band of the strike, the settlement panel says too close to call instead of naming a side, and the model's fair value includes the measured error, so near a tie it doesn't claim more certainty than the price can give.
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, with a 24-hour pass that is not a subscription (Pricing). Information, not advice.