Yes, most NFL markets include overtime, unless the market specifically states otherwise.
Markets that include overtime:
Total Points markets
Line and Handicap markets
Head-to-Head markets
Player statistics (passing, rushing, receiving yards)
Most statistical and performance markets
Markets that do not include overtime unless stated:
Second Half markets
Some Half-Time/Full-Time markets
Certain Quarter or Half-specific markets
If a market excludes overtime, it will be settled based on regular time only.
Example: A Total Points bet includes overtime scoring, while a Second Half market is settled at the end of regulation unless stated otherwise.