$SPX so far day low = yesterday's close 1/2 hour trading day high = 3066.76√ = 55.37833511 -day low = 3055.85√ = 55.27974312 = 0.09859199  + 55.37833511 = 55.4769271 *2 = 3077.68(944)  OR  55.27974312 - 0.09859199 = 55.18115113 *2 = 3044.95(944)