PetroChina briefly became the world’s most valuable company by market capitalization after its 2007 Shanghai listing.
PetroChina, the listed arm of China National Petroleum Corporation, began trading on the Shanghai Stock Exchange in November 2007. Its shares surged on the first day, giving the company an intraday market value reported at roughly $1 trillion and briefly placing it above established giants such as ExxonMobil.
The episode illustrates why market-cap rankings can change rapidly after an initial public offering. PetroChina’s Shanghai shares were priced and traded in a market with strong investor enthusiasm, while its Hong Kong-listed shares had a different price. A company’s market capitalization is calculated from share price multiplied by shares outstanding, so different share classes and exchange prices can affect comparisons.
PetroChina’s valuation later fell substantially from that peak. The company remains a major oil and gas producer, but the 2007 surge is remembered as one of the most dramatic examples of a newly listed company reaching the top of a global market-cap ranking.