Saudi Aramco was valued at about $2 trillion when it listed on the Saudi Exchange in December 2019.
Saudi Aramco's initial public offering began trading on Tadawul in December 2019. The offering initially valued the company at approximately $1.7 trillion, and a subsequent rise in its share price briefly pushed its market capitalization to around $2 trillion.
The company is formally known as Saudi Arabian Oil Company and is majority owned by the government of Saudi Arabia. It is one of the world's largest integrated energy companies, involved in exploration, production, refining, chemicals, and distribution.
The IPO is often discussed alongside the world's largest public companies because its enormous valuation came from a relatively small portion of shares being offered to investors. A market capitalization reflects all shares, not merely the shares sold in the offering.