Investors may wonder whether the time to buy Amazon (AMZN -1.45%) has come and gone. While the company played key roles in pioneering the e-commerce and cloud computing industries, its market cap is now around $2.1 trillion. Given its massive size, investors could reasonably wonder whether relatively smaller growth stocks would make better investments now.

Yet further research shows why investors should not write Amazon off as a mature, slow-growth stock just yet. Three factors indicate that it can still deliver market-beating returns despite its size.

1. Amazon's growth businesses

First, investors should understand that they should not look to Amazon's online sales business for rapid expansion. With that part of the business logging single-digit percentage revenue growth for the past several quarters, it is likely not driving increases in Amazon stock.

Amazon Web Services (AWS) is a different story. It continues to be the cloud infrastructure industry's leader. Additionally, its ability to apply artificial intelligence (AI) and run AI workloads gives it a critical role in today's tech industry.

Moreover, its revenue for the first three quarters of 2024 grew by 18% to $79 billion, outpacing the company's 10% overall growth. Most importantly, 62% of Amazon's operating income came from AWS, demonstrating why it's arguably the most critical segment to the company's growth story.

Nonetheless, it is likely not the only part. Within its North America and international segments, it operates digital advertising businesses, third-party seller services, and subscription services that are growing revenues at double-digit percentage levels. Although Amazon does not reveal the separate operating incomes of these businesses, they are likely helping to drive the company's growth.

2. The balance sheet

Not surprisingly, the benefits of Amazon's growth businesses extend to its balance sheet. The company's liquidity is a staggering $88 billion, a level matched by few other companies.

Admittedly, the $58 billion Amazon carries in long-term debt diminishes that liquidity somewhat. Still, it is largely low-interest debt with maturity dates decades into the future. Thus, one can assume that Amazon will probably earn returns from its cash and equivalents stockpile that exceed the interest rates it's paying, which should further bolster its balance sheet.

Moreover, Amazon generated $48 billion in free cash flow over the last 12 months. Cash flows at those levels give it tremendous flexibility to invest in its enterprises or buy new businesses without diminishing its liquidity. Thus, Amazon can afford to maintain its leadership positions in the cloud and AI while it continues to innovate in the businesses tied to e-commerce.

3. Valuation

While it continues to innovate, one sign that the company may have begun to mature is its valuation. Amazon stock historically traded at elevated P/E ratios as it either took losses or accepted reduced profitability to invest more capital back into its businesses. So investors used to Amazon trading at P/E ratios of between 50 and 120 may be surprised to find that its earnings multiple has fallen to about 43.

Moreover, that has happened during a period when the company is reaping the benefits of its investments. In the first nine months of 2024, the company's net income was $39 billion, almost twice as much as its profit of $20 billion during the same period last year.

Analysts believe its net income growth will slow to 20% in 2025. Still, given Amazon's history of high valuations, investors may want to capitalize on today's lower earnings multiple by adding shares.

Investing in Amazon stock

Ultimately, instead of viewing Amazon's massive market cap as a reason to treat it as a value stock, investors should continue to buy Amazon for growth.

Despite its overall size, Amazon includes AWS and many comparatively smaller growth businesses that can keep its revenue growth in the double-digit percentages. Moreover, its staggering liquidity and free cash flow should help keep these businesses and any future enterprises it pursues vibrant.

Finally, Amazon's valuation has fallen relative to its P/E ratios of the past. With its revenue and earnings growth expected to remain robust, growth investors can likely still beat the market by buying and holding Amazon stock.