Martin Luther King Jr. Day is a federal holiday, and that means standard stock market operations pause. The New York Stock Exchange (NYSE) and NASDAQ will be closed, halting all stock, bond, and options trading for the day. While some bond and forex markets may remain open, most investors will find trading platforms offline.

The United States Postal Service (USPS) also observes the holiday. All mail delivery is suspended, and post office locations nationwide will be closed. This affects everything from regular letters to package shipping and in-person services like passport applications. Online tracking tools, however, should still function.

This closure is part of a long-standing tradition for U.S. federal holidays. Investors and senders should plan transactions and shipments for the previous business day or the following Tuesday. Checking with your specific brokerage or local post office for any unusual hours is always a prudent final step.