4217.6 − 87 × 0.1 is 4208.900000000001 in floating point. TopstepX refused
that take-profit ("Invalid price. Price is outside allowed range") on two
GC shorts on 2026-10-02, and with no stop on the leg nothing else was
working: both rode far past their target with no exit. ES and NQ never hit
it because 0.25 is exact in binary; GC and CL ticks aren't.
- onTick puts the measured-fee take-profit and every stop on the grid —
the take-profit away from the entry, the stop toward it — so an averaged
multi-contract fill between ticks is handled the same way.
- A leg's lone take-profit (no stop, or the fallback after a refused
bracket) that the broker refuses now flattens the position and benches
the account for the day, like a refused bracket. An unknown outcome still
places nothing more.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
