Space Exploration Technologies Corp (SPCX)—better known as SpaceX—is learning that what goes up must come down. The stock slid more than 6% on Thursday to below $179, extending losses from the prior session and pushing the total decline past 20% from Tuesday's all-time high. In dollar terms, that's roughly $620 billion in market value vaporized, leaving the company with a market cap of about $2.4 trillion. Just days ago, it briefly became the world's fourth-largest publicly traded company, surpassing both Amazon.com Inc. (AMZN) and Microsoft Corp. (MSFT), and making founder Elon Musk the world's first trillionaire. The honeymoon, it seems, is over.

The trigger for the selloff? SpaceX announced it would acquire AI coding startup Cursor in a $60 billion all-stock deal, resulting in roughly 3.4% dilution for existing shareholders. Morningstar responded by trimming its fair value estimate for the stock to $62 from $63, citing dilution concerns—though it noted that stronger AI monetization could support upside. That's a far cry from the stock's current price, suggesting analysts see significant downside risk.

The pullback marks a sharp reversal from the euphoric debut. According to Vanda Research, retail investors poured nearly $370 million into SpaceX shares during the first three trading sessions—more than four times what they put into Nvidia Corp. (NVDA) over the same period. But the party is cooling. Options trading launched this week, introducing new avenues for bearish bets. Susquehanna analyst Chris Murphy estimates a 15% chance that SpaceX could lose half its value over the next three months as options-driven volatility intensifies, as reported by Forbes. That's a risk that could spill over into ETFs with significant exposure to the stock.

Short SpaceX ETFs Rally As Bears Gain Traction

While long investors are nursing losses, a growing group of inverse ETFs designed to profit when SpaceX shares decline are having a moment. The Defiance Daily Target 2X Short SpaceX ETF (SPCQ), GraniteShares Inverse SpaceX ETF (SNK), and Tradr 2X Short SpaceX Daily ETF (SPCG) all surged nearly 8% on Thursday, with each gaining more than 3% in after-hours trading. The rally in these bearish products underscores how quickly sentiment has shifted. Just days ago, investors were piling into SpaceX amid record retail demand and expectations that it could become the next mega-cap market leader. Now, concerns about dilution from the Cursor acquisition, lofty valuation levels, and the launch of options trading are fueling demand for inverse funds.

The surge in inverse ETFs also highlights the growing ecosystem of single-stock leveraged and inverse products. Similar funds tied to high-profile names like Nvidia, Tesla Inc. (TSLA), and Strategy Inc. (MSTR) have attracted significant trading activity in recent years, and SpaceX appears to be following the same playbook. With options now available and volatility increasing, these products offer traders a way to express short-term views without directly shorting shares.

For ETF issuers, the emergence of both long and short SpaceX-focused products reflects the company's growing importance in the market. For investors, however, the strong performance of bearish ETFs this week serves as a reminder that SpaceX's debut has entered a new phase—one driven less by IPO enthusiasm and more by questions about valuation, execution, and the sustainability of its rapid rise.

Space ETFs Feel the Pressure

The pullback is also being closely watched by investors in space-focused ETFs that quickly embraced SpaceX after its listing. Among the funds with meaningful exposure are the ARK Space Exploration & Innovation ETF (ARKX), the Tema Space Innovators ETF (NASA), and the Procure Space ETF (UFO). Each provides targeted access to companies involved in satellite communications, launch services, aerospace technology, and the broader space economy. While ARKX closed Thursday largely flat, UFO and NASA dipped more than 1%.

SpaceX's size and prominence have made it difficult for thematic fund managers to ignore. For many investors, the company has become the flagship holding of the commercial space industry, meaning sharp swings in its stock price can have an outsized impact on fund performance and investor sentiment toward the sector.

For ETF investors, SpaceX's first major correction may represent an early test of whether the company's long-term potential can outweigh near-term valuation concerns. While the stock remains one of the market's most closely watched names, the recent selloff suggests that dilution fears and valuation scrutiny are beginning to replace the IPO euphoria that fueled its record-breaking debut.