By Teresa Rivas

The SpaceX initial public offering didn't mean all that much to the stock market this past week -- but it could mark the start of the countdown to the end of the bull market sometime in the year ahead.

Space Exploration Technologies, which began trading on Friday, was the market's focus this past week. And how could it not be? It is the biggest IPO in history; it's building a business that seems based on a sci-fi novel; and it's led by a controversial CEO in Elon Musk, who attracts attention -- good and bad -- wherever he goes.

Before the offering, predictions abounded that SpaceX would be too big for the stock market to handle. Instead, it looked like a nonevent. The S&P 500, the Dow Jones Industrial Average, and the Nasdaq Composite all advanced 0.7% for the week. The IPO came, it was digested, and it went.

But to dismiss SpaceX now that the IPO is over would be a mistake. For one thing, the stock could act as a referendum on riskier assets. Artificial intelligence has been the engine of the bull market, and SpaceX is a potential test of how strong investor appetite remains for everything cutting edge. That's a key concern given massive debuts from Anthropic and OpenAI expected this year.

The IPO will also be watched for the impact it has on the tech sector, the driver of returns over the past three years. The tech-heavy Nasdaq Composite has been the biggest beneficiary during the current four-year bull run, and SpaceX will likely gain fast-track entry to the Nasdaq-100. Tech is 37% of the S&P 500, with the Magnificent Seven alone accounting for around a third.

The stock market's dependence on tech was on full display during the week ended June 5, when AI worries caused the S&P 500 to snap a historic nine-week winning streak, and again in recent days, when AI's direction helped fuel big market swings. Tech may stay in the driver's seat. "Momentum" stocks show no signs of slowing down -- the Invesco S&P 500 Momentum exchange-traded fund gained nearly 6% this past week -- and with economic growth and interest rates still supportive, their "path is still higher," if volatile, writes CIBC Capital Markets head of equity Christopher Harvey.

But this is just the first day of the rest of our post-SpaceX lives -- and much will be learned in the months ahead. SpaceX investors will be able to sell more stock before the end of the year, though the lockup release will be staggered rather than coming at one time. Anthropic and OpenAI are also preparing offerings for later this year, meaning even more supply will be arriving for investors. "[The] market may struggle to absorb a wave of mega-IPOs," writes Gavekal Research analyst Tan Kai Xian.

Just the fact that these IPOs are coming to market could signal trouble ahead. History suggests that a spike in equity issuance often precedes a market top, according to Capital Economics markets economist Joe Maher. He notes that net equity issuance turned positive during the fourth quarter of 1999 and peaked during the first quarter of 2000, just as the S&P 500 reached its dot-com peak. Share issuance surged again during the fourth quarter of 2007, just as the benchmark reached its pre-financial-crisis peak. "[S]urging share issuance is a sign speculation is reaching fever pitch," Maher writes.

The market has stars in its eyes. Let's hope it doesn't become a black hole.

Write to Teresa Rivas at teresa.rivas@barrons.com

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June 12, 2026 17:03 ET (21:03 GMT)

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