Shares of Amazon climbed as much as 11% in extended trading on Thursday after smashing earnings expectations for the fourth quarter.

The company's market cap surged above $1 trillion after hours on the back of the powerhouse earnings report. In doing so, it joined Apple, Alphabet and Microsoft, which have all crossed the trillion-dollar threshold. Amazon first reached a $1 trillion market cap in September 2018.

Here are the key numbers:

Earnings per share: $6.47 per share vs. expectations of $4.03 per share, according to analysts surveyed by Refinitiv

$6.47 per share vs. expectations of $4.03 per share, according to analysts surveyed by Refinitiv Revenue: $87.44 billion vs. expectations of $86.02 billion, per Refinitiv

$87.44 billion vs. expectations of $86.02 billion, per Refinitiv Amazon Web Services: $9.95 billion vs. expectations of $9.81 billion, according to FactSet

Revenue grew 21% to $87.44 billion for the quarter, which indicates the company's investments in speedier shipping are leading to more purchases. Last quarter, Amazon claimed customers shopped at record levels during the holiday season and said it quadrupled both one-day and same-day deliveries over the period.

The company also gave upbeat guidance for the first quarter, saying it now expects to report revenue between $69 billion and $73 billion. Amazon CFO Brian Olsavsky told CNBC's Josh Lipton that the company doesn't "have any visibility" on whether the coronavirus will impact its first quarter results. Many U.S. companies have warned the deadly virus could weigh on their business, while others such as Google have limited operations in China, where the majority of cases have been reported.

In the earnings release, Amazon CEO Jeff Bezos said "more people joined Prime this quarter than ever before" and that the company now counts more than 150 million paid Prime members around the world. Amazon last gave an update on Prime subscribers in April 2018, saying it had more than 100 million members in the program.