Box Spread

BOXBOX-E1-X1_X2

Synthetic long at X1, synthetic short at X2 — payoff = X2 − X1 always.

Expiry

Strike X1 (low)

Strike X2 (high)

Pure arbitrage structure. Final payoff at expiry equals the strike width regardless of underlying. Used to lend/borrow synthetic cash via the options market.

Pick an expiry and 2 strikes to build the combo.