In the race to a trillion, Apple is closer than ever.

Buoyed by strong earnings and optimism surrounding the iPhone X, the market value of the tech giant has closed above $900 billion for the first time: $904 billion as of Wednesday. That valuation beat out even Microsoft’s climb toward a trillion dollars during the dot-com boom.

Despite the hype, Apple would not be the first publicly traded company to reach a trillion dollars in market value. That distinction belongs to oil and gas producer PetroChina, which briefly topped $1 trillion on the Shanghai Stock Exchange in 2007.

Apple also would not be the most valuable company in the world. Most experts believe that distinction belongs to state-owned oil giant Aramco, which the Saudis believe could make a $2 trillion IPO.

However, the iPhone maker is the biggest public company in the world. As investors look forward to how sales of the iPhone X fare (figures that won’t show up until 2018), it is a mere 11% push away from the much discussed $1 trillion valuation.

In recent months, analysts and investors have speculated which tech giant would be the first to grow into a trillion dollar company. Names including fast-growing e-commerce giant Amazon, and dark horse Tesla have been thrown into the mix. But Apple is by far the closest, currently commanding a market value about $175 billion above the world’s second largest public company, Google parent Alphabet.

Still, stocks can be volatile, and the optimism surrounding the iPhone X and iPhone 8 could turn to disappointment if sales of the new offerings fail to live up to expectations. Further weakening in the company’s China sales may also be cause for concern.

And unlike Microsoft in late 1999 – which hit an inflation-adjusted $896 billion – Apple has more than just domestic competition to worry about. China has become an incubator for homegrown tech giants, which have been quickly leveraging the spending power of the world’s largest middle class population.

Last year, Alibaba didn’t even rank among the top 10 largest companies by market capitalization and digital giant Tencent just barely made the list. They are now at No. 6 and No. 7, respectively.

Apple shares have gained roughly 60% in the past year, Alphabet is up 32%, and Amazon is up 47%. Shares of Alibaba have risen 94% while Tencent has soared 85% in the same time.

Source: Fortune