Historically, the stock market was simply a physical location in New York City, where market makers and movers got together to bid and ask, shouting across the floor at one another.
The market would shut down when the closing bell rang and nothing would happen until the next day, when the opening bell sounded. Over the past couple of decades, however, investment markets have evolved to include multiple electronic exchanges, after-hours trading and a host of other innovations that essentially mean that the markets can operate in a continuous manner beyond the closing bell.
The NFL season is no different, in that it’s never really over.