1256 Contract
A 1256 Contract, as defined in section 1256 of the U.S. Internal Revenue Code, is any regulated futures contracts, foreign currency contracts, non-equity options (broad-based stock index options (including cash-settled ones), debt options, commodity futures options, and currency options), dealer equity options, and any dealer security futures contracts. For U.S. Federal income tax purposes, mark-to-market accounting is used for each 1256 contract as of the end of each tax year, and such contracts are treated as sold for its fair market value on the last business day of such taxable year (i.e., as "closed").
The Internal Revenue Service (IRS) is not clear on whether QQQ, DIA and SPY options should be treated as section 1256 contracts. On one hand, these are seen as equity options, not within the definition of a 1256 Contract, but others consider them as non-equity option and meeting the definition of a "broad-based" index option. Instead, the IRS grants penalty relief if a broker determines in good faith that an index is, or is not, a narrow-based index, following published guidelines.