Diff Price (Future - Spot)

Diff Line (Future – Spot) plots a grid of spot-price levels derived from the current futures price.

It rounds the current futures price up to the nearest price block (e.g. every 25 points), then subtracts a user‑defined Diff (Future – Spot) to find the main spot level and draws that as the central line. Additional lines are plotted above and below at equal block distances, with labels showing both Future and Spot values (e.g. 4250 (4215)), plus a compact diff info box for quick reference.