What Is the Specific Date for the Deemed Sale under the Mark-to-Market Rule?

The specific date for the deemed sale under the mark-to-market rule (Section 1256) is the last business day of the tax year, typically December 31st. All open Section 1256 contracts are treated as if they were sold at their fair market value on this date, and the resulting gain or loss is recognized for that tax year.

This annual revaluation is mandatory for these contracts.