Amazon closes at an all-time high as it more than doubles its stock price in just 17 months

Amazon shares soared past the $800 mark for the first time Thursday, closing at an all-time high of $804.70 per share.

That gives Amazon a market cap of over $380 billion, more than double its worth from April 2015, when its shares surpassed $400 for the first time.

Amazon's market cap is now the fourth largest in the world, only trailing Apple, Alphabet (Google), and Microsoft.

Amazon's stock has been on an absolute tear lately. In February, its shares were trading at around $550 when the broader tech market collapsed, while it only went across $600 for the first time in October of last year.

Part of Amazon's rise has to do with the company's consistent growth and dominance in both the e-commerce market and cloud computing business. The company passed $100 billion in annual revenue for the first time last year, while keeping up a robust ~30% growth rate even as the company scales.

Its cloud computing business, Amazon Web Services, is now generating $10 billion in annual revenue with a solid 25% margin. Amazon has also posted record profits for three straight quarters, an anomaly for a company known for investing in growth at the expense of losses.

On top of that, Amazon Prime, its massively loyal paid membership program continues to expand, while new initiatives in original programming and harware, like the Echo, keep turning out to be huge successes.

Wall Street seems to expect even more growth. RBC Capital upgraded Amazon's price target to $1,000 in a note published last week, noting strong growth across almost all platforms.

Disclosure: Jeff Bezos is an investor in Business Insider through hispersonal investment company Bezos Expeditions.