You can call the direction right and still lose money on 0DTE time decay. Look at the attached video. On the video, one $SPX 7,670 call falls from $1,869 to $182. SPX sits at 7,623.68 the whole time. Same price. Same strike. Far less money. The loss isn't bad luck. It isn't a wrong call. It's theta. Theta = the value an option loses every hour. Here's the full breakdown 👇 What the surface in the video is pricing: → Left to right is SPX price, back to front is hours left. → At 9:30 AM, with 6.5 hours left, one 7,670 call is worth $1,869. → With 3 hours left and SPX unchanged, it is worth $867. → With 1 hour left, it is worth $182. → By 3:00 PM the model puts it near $182, with VIX at 19.45. Why being right late still loses: → 7,670 is the modeled ceiling, where big call hedges sit. → SPX must reach 7,670 before the clock drains the call. → Today's priced range runs from 7,530 to 7,717. → 93.4 points is the whole move options price for today. → The weekly priced move is plus or minus 208.8 points. 7,623.68 x 19.45% / 15.87 = 93.4 points What to do tomorrow morning: 1. Before 9:30 AM, divide the VIX by 15.87 to get the daily move. 2. Mark 7,577 and 7,670, the halfway lines, as your targets. 3. If SPX has not reached 7,670 with 3 hours left, close the call. The right direction at the wrong hour is still a loss. That is the whole method. It is one division, and the number is 15.87. It is called The 15.87 Rule. It has the decay table: what one 0DTE call is worth at 9:50, at 11:30 and at 3:00 with SPX sitting still. It costs nothing. Click the link below or in my bio.