How Does a “Put” Option Affect the Holding Period of the Underlying Stock?

Buying a "put" option on stock you already hold (a protective put) can "toll" (stop the clock on) the holding period for long-term capital gains purposes if the stock was held for less than one year when the put was acquired. The holding period resumes only when the put is sold or expires.

This rule prevents locking in a gain while continuing to accrue a long-term holding period.