PetroChina was the world’s most valuable company by market capitalization in 2007.
PetroChina briefly reached the top position after its Shanghai listing in November 2007. Its shares surged on the first trading day, giving the company a market value above $1 trillion at the quoted market price.
The valuation was controversial because PetroChina’s Shanghai-listed shares traded at a large premium to its Hong Kong-listed shares. That difference meant the headline market capitalization did not necessarily represent the value investors worldwide were assigning to every share on identical terms.
PetroChina is the listed subsidiary of China National Petroleum Corporation, one of China’s major state-owned energy groups. Its brief position illustrates how market-cap rankings can change rapidly when a large company’s shares experience an exceptional first-day move.