New York (CNN Business) Amazon's profit machine shows little sign of slowing down.

The company said Thursday that it made a record $3.6 billion in profit for the first three months of 2019, more than doubling from $1.6 billion in the year prior. This marks the sixth straight quarter in which Amazon's profits have topped $1 billion and the fourth consecutive quarter of record profits.

Amazon AMZN Shares ofinitially rose 3% in after-hours trading Thursday following the earnings report, before giving up some of the gains.

For years, Amazon was known for bleeding money as it invested heavily in its businesses and rapidly increased revenue. Now it has entered a new era with comparatively sluggish sales growth, but a consistently profitable business.

The steady increase in Amazon's profits is all the more remarkable given how it continues to pour money into fulfillment centers, premium video content, bricks and mortar stores and healthcare . For competitors, the only thing scarier than an Amazon willing to lose money while making these costly investments is an Amazon that can make all these bets without going into the red.

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