Why Is This Considered a “Perfect Hedge” If the Options Are At-the-Money?

A short synthetic future (Short Call + Long Put) is considered a perfect hedge for a long spot position because the combination has a total delta of approximately zero (Long Spot Delta of +1.0, Short Synthetic Future Delta of -1.0). When the options are at-the-money, their individual deltas are near +/-0.5, making the synthetic future's delta close to -1.0.

This perfect offset means the portfolio's value will not change with small movements in the underlying price, achieving a perfect, though static, hedge.