SpaceX Has Turned Space Investing Into One of the Hottest Trades of 2026. But Which ETF Is Actually Worth Buying?

Tema Space Innovators ETF (NASA) has a higher expense ratio at 0.75% versus 0.60% for First Trust Indxx Aerospace & Defense ETF (MISL), but a much larger AUM of $2.5 billion versus $804.5 million. NASA is a more focused, active space-innovation fund with top holdings like Rocket Lab, MDA Space, and AST SpaceMobile, while MISL offers broader exposure to established defense and aerospace names such as Palantir, GE Aerospace, and Boeing. The article favors MISL for long-term investors due to lower cost and more stable cash-flowing holdings, while noting NASA's volatility and SpaceX-linked speculation.

Analysis

The cleaner expression here is not "space vs defense" but duration of cash flows. MISL is effectively a quality/defense-industrials basket with program visibility, while NASA is a financing-sensitive venture proxy whose mark-to-market is dominated by sentiment around private-space optionality. That makes NASA much more exposed to rate shocks, IPO windows, and secondary-market appetite for pre-profit growth, whereas MISL should behave more like an industrial/defense factor with better downside capture in risk-off tapes.

Second-order, NASA’s concentration in a few names creates a hidden supply of volatility into the underlying equities: sustained ETF inflows can compress spreads and support follow-on issuance for satellite/launch companies, but it also raises the probability of crowded positioning and air-pocket drawdowns when momentum cools. ASTS is the clearest marginal beneficiary because it sits at the intersection of space thematic enthusiasm and telecom optionality, but it is also the easiest source of de-risking if the theme stumbles.

The market may be underestimating how much of NASA’s upside is tied to one or two narrative catalysts, especially the private-space ecosystem and SpaceX-related optionality. If issuance stays open and launch cadence improves, the theme can run for months; if a single high-profile execution miss or valuation reset hits the private market, flows can reverse quickly. By contrast, the defense sleeve has a more durable bid from government procurement, which should limit drawdowns and make any pullback in MISL a higher-conviction entry than chasing NASA after a strong run.

Key Decisions for Investors

• Long MISL / short NASA as a 3-6 month relative-value pair: express a preference for cash-flow visibility over narrative beta; target outperformance if risk appetite fades or rates back up.
• Buy ASTS on 20-30% pullbacks only, with a 1-2 month time horizon: it is the highest-beta beneficiary of continued space inflows, but position size should be capped because momentum unwind risk is large.
• Use call spreads on MISL instead of outright shares for a 6-9 month bullish view: better risk/reward if defense spending remains resilient, with less exposure to theme de-rating.
• Fade NASA strength into new highs via small short or put spread exposure: the risk/reward improves when the ETF trades on flow rather than fundamentals, especially after a rapid AUM expansion.
• Watch PLTR and GE as secondary beneficiaries of defense/industrial allocator rotation; add on dips if sector leadership broadens beyond pure space names.