The world’s most valuable company is scaling new heights. As of Sept. 1, Apple’s stock was up more than 40% year-to-date and its market capitalization had reached a new peak of nearly $850 billion. The tech giant’s share price slumped in late September, pushing Apple’s market value back down below $800 billion. But the stock’s powerful surge throughout the course of the year has fueled speculation that sales of the company’s new iPhone models—the iPhone 8, iPhone 8 Plus, and iPhone X—could soon push Apple’s value over $1 trillion. While remarkable, Apple’s rise is not without precedent. Adjusted for inflation, Microsoft’s value climbed higher in the dotcom boom, to $897 billion, than Apple’s is now. And in 2007, with crude prices on the rise, voracious demand for new shares of PetroChina on the Shanghai Stock Exchange caused the Chinese oil and gas company’s market value to briefly top $1 trillion. Apple’s investors are hoping for a more lasting achievement.
A version of this article appears in the Oct. 1, 2017 issue of Fortune.