Apple was the first company to surpass a $1 trillion market capitalization during an intraday trading session.
Apple crossed the trillion-dollar level on August 2, 2018, while its shares were trading during the day. The company’s market capitalization is calculated from its share price and the number of shares outstanding, so the threshold can be reached before the market closes.
The event was widely reported because it symbolized the scale of Apple’s consumer technology business. The iPhone was the main driver of the company’s growth, supported by the App Store and a large installed base of customers.
Intraday and closing valuations are different measurements. A company may briefly exceed a round-number market cap and then finish below it. Apple’s achievement is therefore best described as the first intraday crossing of the $1 trillion mark by a public company.