Brett Schafer, The Motley Fool

Sun, Jun 15, 2025, 6:45 AM6 min read

• Amazon's durable growth should help it generate strong returns over the long haul.

• Alphabet's cheap present valuation and its innovative history make it a buy today.

• 10 stocks we like better than Amazon ›

Building a retirement portfolio that's worth a million dollars is not an insurmountable task. All it takes is a few decades of consistently adding relatively reasonable amounts of money to a diversified stock portfolio every month.

If, for example, your portfolio's value is $50,000 today, and you add $200 a month to it steadily from here, it will be worth over $1 million in 30 years, assuming an average rate of return of 10% annually. And that's not an unreasonable assumption -- that's been the market's average annualized rate of return over the long haul.

If you have savings sitting in your bank account earning close to zero in interest, perhaps this can be an inspiration to start up that investment account. The best time to begin was yesterday; the second best time to begin is now.

But what stocks should you buy for your portfolio? To generate solid long-term returns, you cannot go wrong with some technology giants that are trading today at reasonable prices. Here's why Amazon (NASDAQ: AMZN) and Alphabet (NASDAQ: GOOG) can help lift your portfolio's value past the $1 million mark by the time you retire.

Steady growth has been the name of the game at Amazon, and that has made it a monster stock to own over the last few decades. The company has a dominant position in e-commerce in the United States -- and a few other countries as well -- while simultaneously leading the global cloud computing market with its Amazon Web Services (AWS) division.

E-commerce still has plenty of market share it can steal from physical retail, even in Amazon's home country. E-commerce as a percentage of total retail sales in the United States sat at just 16.2% as of the first quarter of 2025. Despite Amazon's large presence and popularity, online shopping does not account for even $1 out of every $5 spent at retail. While e-commerce's share will not ever approach 100% due to items like fresh groceries -- although Amazon and others are working hard to deliver these, too -- e-commerce should become a much larger piece of the pie in the years to come.

Amazon's North American retail sales grew by 8% year over year last quarter, while international sales grew 8% as well when factoring out foreign currency fluctuations. Those revenues could easily keep growing at similar rates for years.