The opening bell for the New York Stock Exchange (NYSE) has rung at 9:30am since 1985 when it was changed from 10:00am. The bell starts the daily trading session, which is the time in which all stocks are bought and sold on the trading floor. Until relatively recently, the technology to trade stocks from outside the trading floor didn’t even exist, so the trading session was really the only time when trading took place.

Now trading can be done at all hours from anywhere on the planet – even from your cell phone. However, the majority of trading is still done during the trading session. The board of the NYSE has discussed several times making the bell earlier to extend normal trading hours, but the hours haven’t changed for over 20 years.