Should you buy SpaceX stock in September?

Space Exploration Technologies (SpaceX) went public on June 12, and it has already sent investors on a volatile ride. Despite a 34% decline from its all-time high, SpaceX stock is still expensive by one traditional valuation metric. However, if investors believe Elon Musk's long-term revenue forecast will come to fruition, then SpaceX stock might actually be a bargain today. Space Exploration Technologies (NASDAQ: SPCX) went public on June 12, and its stock quickly soared to a record high of $225. However, it has since plummeted by 34% and closed at $147.95 last Friday, Sept. 4. SpaceX was founded by Elon Musk in 2002 to reduce the cost of space travel. It now has three commercial businesses spanning space transportation, satellite internet connectivity, and artificial intelligence (AI) infrastructure, and Musk is predicting they will generate significant revenue growth over the next few years. Where to invest $1,000 right now? Our analyst team just revealed what they believe are the 10 best stocks to buy right now, when you join Stock Advisor. See the stocks » Although SpaceX stock is still technically expensive, should investors take the opportunity to buy the recent dip in September? SpaceX uses its Falcon 9 and Falcon Heavy reusable rockets to launch over 2,500 tons worth of commercial payloads into orbit each year on behalf of businesses and government organizations. The company already has a 90% market share in this industry, but it believes demand could grow to 10 million tons as enterprises scramble to send advanced satellites and AI infrastructure into space. So there is still plenty of room for growth. But with an addressable market of $370 billion right now, that isn't SpaceX's most valuable opportunity by a long shot. The company estimates there is a whopping $1.6 trillion market for satellite internet connectivity, and it's still very early days. SpaceX has launched around 10,200 Starlink satellites into orbit, which were beaming internet access to 12 million customers here on Earth as of June 30. That number doubled from 6 million in the year-ago period. But then there is the AI market, which could be worth $26.5 trillion across infrastructure, enterprise applications, and consumer subscriptions. SpaceX acquired Elon Musk's start-up xAI earlier this year, which came with a series of centralized data centers such as Colossus and Colossus II. The company is using this infrastructure to further develop its Grok AI models, but it's also renting spare computing capacity to other businesses, including Anthropic, Reflection AI, and Alphabet. In the future, SpaceX wants to launch solar-powered AI infrastructure into orbit, where it won't need expensive energy solutions or complex cooling systems. The company developed a new satellite called Starmind, which uses a variant of Nvidia's Vera Rubin AI data center systems, and it will beam data back to Earth via the existing Starlink network. No other company has an established distribution network comparable to Starlink, so SpaceX would enter the space-based AI infrastructure business with a massive head start over the competition. It's one of the key reasons why Musk believes the company could achieve $1 trillion in annual revenue by 2030. SpaceX generated $7.8 billion in total revenue during the second quarter of 2026 (ended June 30), a 92% increase from the year-ago period. It was broken down as follows: SpaceX Segment Q2 Revenue Revenue Growth (Year Over Year) Space $0.962 billion 29% Connectivity $4.291 billion 66% AI $2.561 billion 247% Data source: SpaceX. While connectivity contributed the most revenue in Q2, the AI segment is rapidly catching up thanks to its blistering growth rate. In fact, chief financial officer Bret Johnsen thinks the AI business could achieve annual run rate revenue of $100 billion by the end of 2026, due to the enormous demand for computing capacity. With that kind of growth, Musk's $1 trillion revenue forecast for 2030 doesn't seem so far-fetched. But valuing a company based on its forward projections can be risky, because there is no guarantee they will come to fruition. What's known for sure is that SpaceX generated $23 billion in total revenue over the last four quarters, so based on its market capitalization of $2 trillion, its stock has a sky-high price-to-sales (P/S) ratio of 86.9. That makes it 14 times as expensive as the Nasdaq-100 index, which has a P/S ratio of 6.2. Simply put, SpaceX looks heavily overvalued compared to a basket of America's largest technology stocks. Assuming that the company will deliver $105 billion in revenue during 2027 as Wall Street expects (according to Yahoo Finance), its forward P/S ratio is 19. While that is a far more reasonable valuation, it's still elevated relative to the broader market. So, should investors buy SpaceX stock this month? The answer depends on their time horizon. Those seeking strong gains over the next year or two might be left disappointed, but those who are willing to hold the stock beyond 2030 could earn a very nice return, particularly if Musk's trillion-dollar revenue forecast becomes a reality. Before you buy stock in Space Exploration Technologies, consider this: The Motley Fool Stock Advisor analyst team just identified what they believe are the 10 best stocks for investors to buy now… and Space Exploration Technologies wasn't one of them. The 10 stocks that made the cut could produce monster returns in the coming years. Consider when Netflix made this list on December 17, 2004... if you invested $1,000 at the time of our recommendation, you'd have $421,997!* Or when Nvidia made this list on April 15, 2005... if you invested $1,000 at the time of our recommendation, you'd have $1,413,876!* Now, it's worth noting Stock Advisor's total average return is 978% — a market-crushing outperformance compared to 213% for the S&P 500. Don't miss the latest top 10 list, available with Stock Advisor, and join an investing community built by individual investors for individual investors. See the 10 stocks » *Stock Advisor returns as of September 8, 2026. Anthony Di Pizio has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Alphabet and Nvidia. The Motley Fool has a disclosure policy.