Stock market holidays are determined by the country in which the exchange is located. Holidays such as New Year's Day, Christmas, and Good Friday are common. Canada and the United States celebrate Thanksgiving on different days. Most Commonwealth countries observe Boxing Day after Christmas. These countries also close their exchanges on that day.

Stock exchange holidays vary depending on the country and the exchange. However, some common holidays observed by many stock exchanges worldwide include:

1. New Year's Day: January 1st
2. Martin Luther King Jr. Day: Third Monday in January (for U.S. exchanges)
3. Presidents' Day: Third Monday in February (for U.S. exchanges)
4. Good Friday: Friday before Easter Sunday (dates vary)
5. Memorial Day: Last Monday in May (for U.S. exchanges)
6. Independence Day: July 4th (for U.S. exchanges)
7. Labor Day: First Monday in September (for U.S. exchanges)
8. Thanksgiving Day: Fourth Thursday in November (for U.S. exchanges)
9. Christmas Day: December 25th

These holidays typically result in the closure of stock exchanges, meaning trading does not occur on these days. It's essential for traders and investors to be aware of these holidays as they can affect trading volumes and market liquidity, leading to potential fluctuations in stock prices before and after the holidays.