If I Had $10,000 to Invest Today, Here's the Trillion-Dollar Stock I'd Buy Instead of SpaceX

Space Exploration Technologies (NASDAQ: SPCX) went public on Friday, June 12, and promptly soared to an all-time high of $225.64. But by the market close on Friday, June 26, the stock had fallen by 32% to $153.23.

The space transportation and internet connectivity company, which was founded by Elon Musk, still has a market capitalization of $2 trillion. With just $19.3 billion in trailing 12-month revenue, its stock is trading at a price-to-sales (P/S) ratio of 103, making it 15 times as expensive as the Nasdaq-100 technology index. As a result, I think more downside could be on the way for SpaceX.

If I had $10,000 to invest in one stock for my diversified portfolio, I'd definitely look elsewhere. Here's why Amazon (NASDAQ: AMZN) might be the better long-term buy.

Image source: The Motley Fool.

Amazon's e-commerce business is increasingly profitable

Amazon is a tech conglomerate with a presence in e-commerce, cloud computing, streaming, digital advertising, and more. It's best known for its e-commerce business, which was started in 1994 and now accounts for more than one-third of all online sales in the U.S.

In 2023, Amazon split its American fulfillment network into eight distinct regions to shorten the distance each order travels before reaching its customer. This continues to reduce logistics costs, and it enables Amazon to provide same-day delivery to more customers, which increases their satisfaction.

Amazon is also investing heavily in artificial intelligence (AI) and robotics to make its fulfillment centers more efficient. These innovations, combined with the regionalization efforts, are improving the profitability of the e-commerce business. That business has historically operated on razor-thin margins because Amazon focuses on giving customers the lowest possible prices.

During the first quarter of 2026 (ended March 31), Amazon's North American and International e-commerce segments combined to generate $9.7 billion in operating income, which was up by a whopping 47% compared to the year-ago period. In other words, e-commerce is quickly becoming a tailwind for Amazon's overall earnings, which has positive implications for its stock price (we'll explore this further in a moment).

A leader in artificial intelligence infrastructure

Amazon Web Services (AWS) is the world's largest cloud computing platform, offering hundreds of solutions to help businesses thrive in the digital age. But Wall Street is squarely focused on its growing portfolio of AI services, which is fueling a new growth phase.

AWS operates data centers fitted with the latest graphics processing units (GPUs) from suppliers like Nvidia, and it rents the computing capacity to other businesses that use it to develop AI software. It also designed its own chips, like Trainium2, which offers 30% better price performance than competing hardware -- though it was recently superseded by Trainium3, which is up to 40% better.

AWS Bedrock is a platform that lets businesses access the latest, ready-made large language models (LLMs) from top developers like OpenAI and Anthropic to accelerate their AI software development. Bedrock had over 125,000 customers at the end of Q1 2026, and Amazon said that its spending increased by an eye-popping 170% compared to three months earlier in the fourth quarter of 2025.

AWS generated $37.5 billion in total revenue during Q1, representing 28% growth compared to the year-ago period. It was the third straight quarter in which that growth rate accelerated, which highlights the incredible demand for AI services.

Perhaps the best is yet to come. AWS has a $364 billion order backlog from customers who are waiting for more data center infrastructure to come online, not including a recent deal with Anthropic worth $100 billion on its own.

Amazon stock trades at an attractive valuation

Amazon stock has a P/S ratio of just 3.3, so not only is it substantially cheaper than SpaceX, but it's also cheaper than the Nasdaq-100, which trades at a P/S ratio of 6.8. However, Amazon stock also looks very attractive when valued based on its earnings, thanks in part to the growing profitability of its e-commerce business.

The company has generated trailing 12-month earnings of $8.37 per share, placing its stock at a price-to-earnings (P/E) ratio of 27.1. Once again, it's much cheaper than the Nasdaq-100, which trades at a P/E ratio of 34.4.

Amazon stock also has a forward P/E ratio of 22.9, based on Wall Street's consensus earnings estimate for 2027.

Data by YCharts.

That means Amazon stock would have to soar by 50% by the end of next year just to trade in line with the P/E ratio of the Nasdaq-100 (assuming it remains constant). That isn't unrealistic, considering the stock spent most of the last five years with a P/E of above 30.

As a result, I think Amazon has far more upside potential than an expensive name like SpaceX.

Anthony Di Pizio has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Amazon and Nvidia. The Motley Fool has a disclosure policy.