Gap risk is the risk that a price moves discontinuously across a level at which a position’s value or hedge changes, a barrier, a strike near expiry, or a stop, so that the hedge planned at that level is executed at a worse price or not at all.
Ejemplos
Example 15.15 (A gap through a reverse barrier)
An up-and-out call, strike 100, barrier 120, has one month left, and the spot is 119. It is worth 1.38 and its delta is : a rise brings the barrier closer and destroys the payoff (Figure 15.4). The seller hedges by selling 1.37 shares. If the spot moves to 119.5, the hedged position’s P&L is . If it gaps to 125, the option dies, and the seller gains its 1.38, but the short shares lose : a net loss of 6.81, five times the premium.