Apple briefly became the world's most valuable company by market capitalization in July 2020 after overtaking Saudi Aramco.
Apple surpassed Saudi Aramco in late July 2020 as a rally in Apple's shares pushed its market capitalization above the oil producer's value. The comparison was especially notable because the two companies represented very different industries: consumer technology and petroleum.
Apple's market value benefited from investor expectations for strong iPhone demand, expanding services revenue, and the resilience of its business during the COVID-19 pandemic. Saudi Aramco's valuation was affected by oil-market conditions and the extraordinary demand shock of 2020.
The ranking was temporary and depended on the closing prices and share counts used for comparison. Companies can trade places frequently, so “world's most valuable” should always be tied to a date or market session.