Skip to content

Replicate a put with short underlying and cash

The same strike-100 model gives put holdings Δ=−0.4 and current cash 49.523810.

On this page

Read the put’s state amounts

With terminal prices 130 and 80, the put pays zero and 20. Keep higher-minus-lower ordering for both payoff and underlying differences. The period factor remains 1.05.

Solve the short underlying component

Δ=(0−20)/(130−80)=−0.4. In the lower state the underlying component is −32. Reaching payoff 20 requires terminal cash 52, with current cash 52/1.05=49.523810.

Verify the signs in each state

Put state check
StateUnderlying componentTerminal cashMatched put
Higher−52+520
Lower−32+5220

Reconcile the current amount

The short underlying component has current value −40. Add current cash 49.523810 to get put value 9.523810. The negative holding is a model position, not a negative option value or a reason to take its absolute value.

Further references