Developer grades own ML options forecasts after June expiry, scores worse than coin flip

A developer publicly committed in May to grading Helium's machine-learning probability forecasts for two AAPL options contracts expiring on June 26, 2026. When the contracts expired, AAPL closed at $283.78 on Nasdaq, leaving the $310 call out of the money and the $295 put in the money. The mean Brier loss across both contracts came out to 0.3846, worse than the 0.25 a naive 50-50 coin-flip model would have scored. The call forecast was closer to the actual outcome than the market-implied probability, but the put forecast suffered a high loss of 0.5929 because the model had significantly understated the chance of the stock falling that far. The developer acknowledged the sample size of just two contracts is too small for calibration conclusions, framing the exercise as a discipline of publicly logging and then honestly grading predictions.