SpaceX stock gains index weight as Nasdaq 100 allocation nearly doubles

Space Exploration Technologies Corp (ISIN US84615Q1031) stock closed at 152.71 USD on the Nasdaq on September 18, 2026, implying a market capitalization of roughly 2.07 trillion USD based on recent market data. As Capital Futures reported on September 21, 2026, SpaceX’s weight in the Nasdaq 100 index is set to increase from about 1.28 percent to 2.82 percent, calculated using the September 18, 2026 closing price.

Nasdaq 100 weight rises to 2.82 percent

According to Capital Futures, the new 2.82 percent Nasdaq 100 weight for SpaceX becomes effective in pre-market trading on September 21, 2026 and is based on the final index data using the September 18, 2026 close. This represents more than a doubling from the previous roughly 1.28 percent weight, highlighting how the free float of SpaceX shares has increased since the company’s initial public offering. The same report notes that SpaceX’s market value above 2 trillion USD currently ranks it among the largest seven companies in the Nasdaq 100, even though its index weight had previously lagged because of a relatively low free-float share. For index-tracking exchange-traded funds, the higher 2.82 percent allocation means passive capital rebalancing flows that could reach into the tens of billions of dollars in aggregate, as funds raise their SpaceX holdings to match the new index composition.

As TTV summarized on September 21, 2026, the gap between SpaceX’s rank by market capitalization and its smaller previous weight reflected the unusually tight free float after its IPO. With post-IPO lock-ups gradually expiring, more shares are now available for trading, allowing index weights to climb toward levels more consistent with the company’s size. For investors, the quantified jump from roughly 1.28 percent to 2.82 percent provides a concrete signal that passive ownership will structurally increase at the new rebalance.

NASA contract adds 946 million USD of crew mission value

In parallel with the index news, SpaceX secured a significant expansion of its human spaceflight business. As Investor Taiwan reported on September 21, 2026, NASA announced on September 18, 2026 that it is expanding its Commercial Crew Transportation contract with SpaceX by up to three additional Crew Dragon missions to the International Space Station. The added missions have a maximum contract value of 946 million USD, extending the collaboration between NASA and SpaceX through 2030. While exact margins were not disclosed, the incremental revenue potential of up to 946 million USD strengthens the company’s backlog in its crew transportation segment.

The same report notes that SpaceX’s stock closed at 152.71 USD on September 18, 2026, down 2.10 USD or 1.36 percent on the day, after the company delayed its fourteenth Starship test flight from September 22 to September 28, 2026. That move came as SpaceX prepared a mission profile in which the Super Heavy booster aims for a sea landing, while the Starship upper stage targets a controlled splashdown in the Pacific Ocean west of Chile. The combination of a roughly 1.36 percent daily share price drop and the 946 million USD incremental NASA contract illustrates how operational scheduling and contract wins can influence short-term sentiment, even when the longer-term revenue pipeline is reinforced.

Price level, valuation and recent flows

Recent market data compiled by Top1Markets show that SpaceX closed at 152.71 USD on September 18, 2026 on the Nasdaq, corresponding to a market capitalization of approximately 2.07 trillion USD. Based on that closing price and trailing revenue, the portal cites a trailing price-to-sales ratio of about 89.95 times and a forward price-to-sales ratio around 24.84 times, referencing StockAnalysis data. This means investors are currently paying almost 90 times the company’s trailing twelve-month revenue and nearly 25 times projected forward revenue, underscoring how the valuation embeds expectations of continued high growth.

The same analysis emphasizes that a price of 152.71 USD leaves SpaceX stock several tens of percent below its post-IPO peak while still within a range that makes it one of the most expensive stocks in the Nasdaq 100 on a sales-multiple basis. For context, the average closing price of 152.71 USD on September 18, 2026 stands near the recent consolidation zone and, according to various portal data, leaves the shares roughly 5 percent below their 160 USD IPO start price. That quantified gap suggests that although the stock has retreated from earlier highs, it remains close to its initial offering level, which may anchor perceptions of fair value for some market participants.

Starship delay and retail outflows as risk factors

On the risk side, several outlets highlight that the short-term price pressure around September 18, 2026 coincided with schedule changes for SpaceX’s flagship Starship program and notable outflows by private investors. As FinanzNachrichten summarized on September 21, 2026, the stock fell 1.36 percent to 152.71 USD on September 18, 2026 after the company postponed the fourteenth Starship flight from September 22 to September 28, 2026. Over the three weeks leading up to that date, private investors reportedly withdrew around 570 million USD net from the stock, suggesting some caution among retail shareholders as the test campaign progresses.

This combination of a 1.36 percent daily decline, a 570 million USD net retail outflow in three weeks and high valuation multiples highlights the sensitivity of SpaceX stock to news about its Starship program. While the NASA contract extension worth up to 946 million USD underpins long-term revenue, any further delay or test anomaly could increase volatility. For long-term observers, the quantified flows and price reaction provide a concrete gauge of how much short-term risk appetite has adjusted even as passive index demand is poised to rise with the Nasdaq 100 weight increase.

Stock price context and trading reference

As of the last completed Nasdaq trading session on September 18, 2026, SpaceX stock closed at 152.71 USD, down 1.36 percent from the prior close, with an intraday range between 149.93 USD and 156.60 USD and a reported trading volume in the several-million-share range. Market portals place the company’s market capitalization at approximately 2.07 trillion USD on that date, with the stock trading close to its IPO reference price of 160.00 USD yet still below its post-IPO peak. This level serves as the reference price for investors tracking SpaceX stock relative to the broader Nasdaq 100 rebalancing.

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