ARK Space and Defense Rockets Past Invesco Aerospace and Defense. Which ETF is Better?

PPA has the larger AUM at $8.0 billion versus ARKX’s $717.3 million and a lower expense ratio of 0.58% versus 0.75%, but ARKX delivered stronger 1-year total return at 58.1% versus 25.1%. Risk is meaningfully higher for ARKX, with beta of 1.41 and a 4-year max drawdown of 25.6% versus PPA’s 0.74 beta and 15.4% drawdown. The article frames PPA as a lower-cost, lower-volatility defense ETF, while ARKX is a more aggressive, tech-heavy space innovation play.

Analysis

The market is still rewarding the higher-beta “innovation” basket, but the more important signal is that the return gap is being earned with a meaningfully different factor mix, not just better stock selection. ARKX’s exposure to space/semicap-adjacent names makes it a higher-duration equity proxy: it should continue to outperform in liquidity rallies, but it is also far more vulnerable if real rates back up or risk appetite de-risks. In contrast, PPA looks like a cash-flow compounding vehicle with defense/industrial characteristics that will likely lag in sharp momentum bursts but should keep defending on drawdowns.

The second-order effect is on the underlying names, especially RKLB and AMD. ARKX’s weight in these higher-beta constituents can create a feedback loop where ETF inflows mechanically tighten float supply and amplify upside in small/mid-cap names, while any reversal can hit them harder than the headline ETF suggests. Meanwhile BA/GE/RTX/LHX benefit from a more orderly capital-allocation regime: they are less dependent on thematic sentiment and more on budget visibility, supplier execution, and order-book conversion, which typically supports lower dispersion and better downside capture.

The contrarian read is that the better-looking recent performance may be front-loaded and partially regime-driven rather than structurally persistent. If the sector remains bid, PPA may quietly win on a risk-adjusted basis because its lower beta and drawdown profile allow larger sizing and less path dependency. If sentiment cools, ARKX’s “active innovation” edge can compress quickly because the basket is crowded in the same long-duration trade that already worked.

This sets up a cleaner expression through pair trades than outright ETF longs. The key question for the next 1-3 months is whether defense budgets and industrial earnings can re-rate enough to narrow the performance gap, or whether the market continues to pay a premium for space optionality and small-cap torque. That distinction matters more than the expense ratio debate, which is now secondary to factor exposure and concentration risk.

Key Decisions for Investors

• Go long PPA / short ARKX as a 1-3 month relative-value trade if real yields rise or equity breadth narrows; target mean reversion after the recent momentum chase, with PPA’s lower beta offering better downside protection.
• For tactical upside, buy RKLB and AMD only on pullbacks and prefer call spreads over stock; the ETF bid can amplify upside, but position sizing should reflect the risk of abrupt de-rating if growth multiples compress.
• Overweight BA, GE, RTX, and LHX as a lower-volatility defense basket for 6-12 months; these names should be less sensitive to factor rotation and can benefit from steadier order-flow visibility than the thematic space cluster.
• Avoid using ARKX as a core holding; if owned, treat it as a momentum sleeve and use a trailing stop or hedge with QQQ puts, because the portfolio’s higher duration makes it vulnerable to any risk-off tape.
• If looking for a cleaner hedge, pair long PPA with a modest short in a technology/growth ETF or QQQ over the next quarter to isolate the defense cash-flow trade from broad market beta.