The space sector’s post-IPO momentum has reversed sharply, with most retail-favorite space stocks deep in the red for July 2026.
Viasat, Inc. (VSAT) and Iridium Communications, Inc. (IRDM) stand as the only two winners in the basket, gaining 8.4% and 4.1% respectively this month.
The rest of the sector has been punished severely, with Rocket Lab (RKLB) sliding 39%, AST SpaceMobile (ASTS) falling 29%, and Momentus (MNTS) plunging 53%.
SpaceX (SPCX) itself dropped 35% and slipped below its $135 IPO price after retreating sharply from its post-listing peak.
The selloff follows SpaceX’s IPO prospectus pitch of a $28.5 trillion total addressable market, which the company called the largest actionable TAM in human history.
That estimate included $370 billion in space solutions, $1.6 trillion in connectivity opportunities, and a staggering $26.5 trillion tied to artificial intelligence.
NYU finance professor Aswath Damodaran was skeptical of those figures even before the IPO, saying the estimate “borders on fantasy” and using materially smaller target markets in his own valuation.
Rising concerns about valuation, execution risk, spending requirements, and post-lockup share supply have compounded the pressure on the broader sector.
Despite weak monthly returns, retail sentiment on Stocktwits showed investors leaning bullish on ASTS and RKLB, creating a notable disconnect between conviction and actual performance.
Watchers for ASTS rose 3% over the past month while RKLB watchers climbed 4%, even as both stocks lost significant ground during that same period.
The divergence is even starker when looking at year-to-date performance, with Viasat returning 102% and Iridium gaining 170% so far in 2026, while ASTS was down 21% and RKLB had lost 6%.
Iridium’s July outperformance had a clear and specific catalyst: Rocket Lab’s $8 billion cash-and-stock takeover deal announced this month.
The deal adds a global communications network, recurring revenue, government customers, 2.5 million subscribers, and valuable L-band spectrum to Rocket Lab’s portfolio.
CEO Peter Beck’s vision of building a vertically integrated rival to SpaceX appears to have given Iridium shareholders a direct and tangible premium.
Viasat’s rally rests on a related but more speculative thesis centered on the growing scarcity and strategic value of its globally coordinated spectrum holdings.
Oppenheimer called Viasat’s holdings one of the largest remaining blocks of globally harmonized spectrum critical to the emerging direct-to-device market.
Raymond James estimates Viasat’s spectrum portfolio could be worth $15 billion, while Oppenheimer believes the company’s core business is approaching a free-cash-flow inflection point.
With Iridium being acquired and Amazon moving to Globalstar, investors now view Viasat as one of the last major standalone spectrum plays in the sector.
On the short side, current Koyfin data shows that Virgin Galactic (SPCE) remains the sector’s biggest bearish target with 34% of its float sold short.
ASTS and BKSY follow at 22% short interest, while S3 Partners noted that only about 22% of ASTS short interest was linked to convertible-bond arbitrage, suggesting most represents an outright bearish bet.
