You asked: what is span margin
Lots, margin, and the costs that decide whether anything survives
Index options trade in fixed lots, writing them requires margin the exchange computes daily, and the round-trip cost is large enough that any measured edge has to be reported net of it before it means anything.
Mayawhat these words mean
Maya reads the desk’s written explainers and the glossary. She holds no market data at all, so she can say what a thing is and cannot say what it is doing today.