Apple was the first company to reach a $1 trillion market capitalization during the 2018 technology boom.
Apple crossed the threshold on August 2, 2018, after its shares rose following a strong quarterly report. The milestone followed years of expansion in iPhone sales, services, accessories, and international markets. Investors also valued Apple's substantial cash generation and share-repurchase program.
A company's market cap is not a balance-sheet line item. It is the current price of one share multiplied by the number of shares outstanding. Consequently, Apple's trillion-dollar status depended on both its share price and its share count, which had been reduced by buybacks.
Amazon, Microsoft, and Alphabet crossed $1 trillion later. The record was therefore about timing, not a claim that Apple had the highest revenue, largest workforce, or greatest physical footprint. Those measurements can produce entirely different rankings.