V4: Rolling IV Re-calibration

v42026-07-03159915.SZ Call K=4.0Every 5 min

Re-snapshot ATM IV every 5 minutes, compute new forecast, compare against rest of day. Track IV drift: forecast IV vs actual IV over time.

Changelog:
v1 → Constant IV from ATM at 9:30 v2 → IV skew interpolation at 9:30 v3 → Multi-day backtest v4 → Rolling re-calibration: new forecast every 5 min with current IV
Best Checkpoint
14:59:00
Best MAE
0.0005
9:30 MAE
0.0093
IV Drift
-9.0%

ATM IV at Each Checkpoint

35.234.433.632.832.009:30:0009:55:0010:20:0010:45:0011:10:0013:04:0013:29:0013:54:0014:19:0014:44:00IV %

Forecast Error by Checkpoint Time

0.00900.00690.00470.00260.000509:30:0009:55:0010:20:0010:45:0011:10:0013:04:0013:29:0013:54:0014:19:0014:44:00MAERMS

IV Drift: Actual - Forecast (by Checkpoint)

0.4-0.3-1.0-1.8-2.509:30:0009:55:0010:20:0010:45:0011:10:0013:04:0013:29:0013:54:0014:19:0014:44:00Drift %

Minute-Level: Error & IV (best checkpoint)

29.246921.933814.62087.3077-0.005409:30:0010:00:0010:30:0011:00:0011:30:0013:29:0013:59:0014:29:0014:59:00ErrorForecast IVActual IV