PetroChina briefly became the world's first company valued at $1 trillion in 2007.
The milestone occurred on November 5, 2007, when PetroChina shares began trading on the Shanghai Stock Exchange. The company's market value surged during its first trading day, briefly exceeding $1 trillion before falling back.
This event is often confused with the later, more durable trillion-dollar milestones reached by companies such as Apple, Microsoft, and Saudi Aramco. PetroChina's valuation was especially short-lived because its share price dropped sharply after the initial surge.
PetroChina is the listed arm of China National Petroleum Corporation, one of China's major state-owned energy groups. Its market value is calculated by multiplying its share price by the number of outstanding shares, so it can change rapidly even when the underlying business changes more slowly.