Opening Bell
The bell rung at 9:30 a.m. ET each weekday signaling the official start of regular trading on US stock exchanges.
What is Opening Bell?
The opening bell refers to the bell rung at 9:30 a.m. Eastern Time each business day at the New York Stock Exchange (NYSE) and Nasdaq to mark the official start of the regular trading session, which runs until the closing bell at 4:00 p.m. ET. The minutes immediately following the opening bell are typically the most volatile and highest-volume period of the trading day, as overnight news, pre-market earnings releases, and accumulated buy and sell orders flood the market simultaneously. Companies completing IPOs, dignitaries, athletes, and charitable organizations are frequently invited to ring the bell, making it a high-profile public-relations moment. The corresponding closing bell ends the regular session and triggers the official daily closing prices used in fund NAV calculations.
Example
On the morning of a major earnings release, a large-cap tech stock opens at $185 at the 9:30 a.m. bell, up 7% from the prior close, as overnight orders accumulated after the company reported results after Thursday's close. More than 5 million shares trade in the first ten minutes — three times the stock's average hourly volume.
Source: NYSE — Trading Information