PetroChina briefly became the world's most valuable publicly traded company on its first day of trading in October 2007.
PetroChina’s Shanghai listing began on November 5, 2007, and its shares surged dramatically during the first session. The rise temporarily gave the company a market value exceeding that of established global leaders such as ExxonMobil.
The episode is often cited in histories of market capitalization because the valuation was extraordinarily large relative to the company’s underlying earnings. The initial excitement did not last: PetroChina’s share price fell sharply afterward, and its market value moved far below the opening peak.
PetroChina is the publicly traded arm of China National Petroleum Corporation, one of China’s major state-owned energy groups. It should not be confused with Saudi Aramco, whose much later public listing became one of the world’s largest initial public offerings.