Microsoft (MSFT) crossed the threshold of a $1 trillion valuation this morning shortly after the stock market opened.
Rising sales in its first quarter earnings release boosted its share price. The stock was last up about 4%.
Whether it's a day for the books remains to be seen. Microsoft's market capitalization will be determined by its closing price, rather than its highest level during intraday trading.
Arch rival Apple (AAPL) closed with the magical $1 trillion valuation in August last year, but has since fallen below that threshold. Amazon (AMZN) reached the level in September, but only during intraday trading. Both Apple and Amazon are due to report earnings today and tomorrow, which could boost their shares — and make the $1 trillion mark reachable again.