Use this in the leg’s Strike Fx field in the Position Builder:
Use ATM SPOT to anchor to the spot price. The plain ATM keyword anchors to the futures price.
You can either add the points to the result (for example + Number(300)) or use the “ATM +/- n Step(s)” offset. The offset counts strikes, not points, so do not put a point value there. Strike intervals change over time, so check the live option chain.
Edited with AI from the original Tradetron article, checked against current docs (Oct 2026). Spot something wrong? Tell us in the Community.