RKLB vs ASTS: Stock Returns, Risk & Volatility (2026)

Q: Which is a better investment: RKLB or ASTS?

Over the past year, Sharpe ratios were similar (RKLB 1.91 vs ASTS 1.91), but ASTS led on total return (ASTS +314.2% vs RKLB +255.7%). On risk, RKLB was less volatile (RKLB 83.6% vs ASTS 98.7%), RKLB had a smaller max drawdown (RKLB -43.0% vs ASTS -47.0%), and RKLB had less severe losses on the worst 5% of days (Expected Shortfall of RKLB -11.00% vs ASTS -11.75%).

Written by Gale Finance Team

Reviewed by Sid Kalla CFA Charterholder

Quick answer

Which is a better investment: RKLB or ASTS?

Over the past year, ASTS had higher returns (+255.7% vs +314.2%).

Total Return

RKLB +255.7%

ASTS WIN +314.2%

Sharpe Ratio

RKLB 1.91

ASTS 1.91

Annualized Volatility

RKLB WIN 83.6%

ASTS 98.7%

Max Drawdown

RKLB WIN -43.0%

ASTS -47.0%

Analysis period: 2025-04-14 to 2026-04-10

RKLB Total Return

↑ +255.7%

ASTS Total Return

↑ +314.2%

Relative Performance of RKLB vs ASTS (Normalized to 100)

RKLB ASTS

Normalized to 100 at start date for comparison

Key Takeaways

Total Return: RKLB delivered a +255.7% total return, while ASTS returned +314.2% over the same period. ASTS outperformed on total returns.
Risk-Adjusted Return (Sharpe Ratio): Both assets posted similar Sharpe ratios (1.91 vs 1.91), indicating comparable risk-adjusted performance.
Volatility (Annualized): ASTS was more volatile, with 98.7% annualized volatility, versus 83.6% for RKLB.
Maximum Drawdown: RKLB's maximum drawdown was -43.0%, while ASTS experienced a deeper drawdown of -47.0%.
Tail Risk (VaR & Expected Shortfall): At the 5% level (daily log returns), RKLB's VaR was -9.44% and its Expected Shortfall (CVaR) was -11.00%; ASTS's were -9.98% and -11.75%. VaR is the cutoff; Expected Shortfall is the average move on the worst days.
Skew & Kurtosis: Skew: RKLB -0.15 vs ASTS 0.01. Excess kurtosis: RKLB 0.17 vs ASTS -0.10. Negative skew leans downside; higher excess kurtosis means fatter tails.
Tail Days & Extremes: 2σ tail days (down/up): RKLB 9/4, ASTS 6/9. Worst day: RKLB -12.57% (2025-09-16) vs ASTS -15.17% (2026-02-12). Best day: RKLB +17.69% (2025-12-19) vs ASTS +18.25% (2025-12-04).
Risk ratios: Sortino - RKLB: 2.98 vs. ASTS: 3.07 , Calmar - RKLB: 6.07 vs. ASTS: 6.83 , Sterling - RKLB: 12.41 vs. ASTS: 13.06 , Treynor - RKLB: 0.57 vs. ASTS: 0.65 , Ulcer Index - RKLB: 17.75% vs. ASTS: 20.81%

Rocket Lab USA vs AST SpaceMobile Correlation

0.61 Average Correlation

Rocket Lab USA and AST SpaceMobile are strongly correlated over the past year. With a correlation of 0.61, these assets tend to move together, limiting diversification benefits.

For portfolio construction, this strong correlation means holding both RKLB and ASTS provides limited risk reduction — they're likely to decline together in downturns.

Metric	Value
Current (30-day)	0.80
Average (full period)	0.61
Minimum	0.11
Maximum	0.89

Correlation measures how closely two assets move together. Values near +1 indicate strong co-movement, near 0 indicates independence, and negative values indicate inverse movement.

Investment Comparison

If you invested $10,000 in each asset on April 14, 2025:

RKLB $35,572.4 +255.7%

ASTS $41,422.96 +314.2%

Difference: $5,850.56 (ASTS ahead)

Rocket Lab USA and AST SpaceMobile: Risk Analysis

Rocket Lab USA experienced its maximum drawdown of -43% from 2025-10-15 to 2025-11-20. It took 29 days to recover.

AST SpaceMobile experienced its maximum drawdown of -47% from 2025-10-15 to 2025-11-20. It took 47 days to recover.

Smaller drawdowns and faster recoveries indicate lower downside risk and greater resilience during market stress.

Sharpe Ratio of RKLB and ASTS

RKLB Sharpe Ratio

↑ 1.91

ASTS Sharpe Ratio

↑ 1.91

Sharpe ratio measures return per unit of risk (volatility). A higher Sharpe indicates better risk-adjusted performance. Both assets posted similar Sharpe ratios (1.91 vs 1.91), indicating comparable risk-adjusted performance.

A Sharpe above 1.0 is generally considered good, above 2.0 is excellent. Negative Sharpe means the asset underperformed the risk-free rate. Calculated on each asset's full 365-day lookback of available prices and annualized using the asset calendar (365 for crypto, 252 trading days for equities/ETFs/metals).

Sortino Ratio of RKLB and ASTS

RKLB Sortino Ratio

↑ 2.98

ASTS Sortino Ratio

↑ 3.07

Sortino ratio measures return per unit of downside risk. Unlike Sharpe, it only counts downside deviation (returns below the target return). ASTS had better downside-adjusted returns.

A higher Sortino is better. It's useful when upside volatility is common (crypto is the obvious example). Downside deviation: RKLB 53.5% vs ASTS 61.4%. Calculated on each asset's full 365-day lookback of available prices, using the daily risk-free rate as the target return, and annualized using the asset calendar (365 for crypto, 252 trading days for equities/ETFs/metals).

Calmar Ratio of RKLB and ASTS

RKLB Calmar Ratio

↑ 6.07

ASTS Calmar Ratio

↑ 6.83

Calmar ratio compares CAGR to maximum drawdown. Higher Calmar means more return per unit of worst drawdown. ASTS posted the higher Calmar ratio.

Calmar is computed on each asset's full 365-day lookback and uses the max drawdown over that same window.

Sterling Ratio of RKLB and ASTS

RKLB Sterling Ratio

↑ 12.41

ASTS Sterling Ratio

↑ 13.06

Sterling ratio measures excess return per unit of average drawdown (typically drawdowns worse than 10%). ASTS posted the higher Sterling ratio.

Sterling uses average drawdown events deeper than 10% and subtracts the risk-free rate to report excess return.

Treynor Ratio of RKLB and ASTS

RKLB Treynor Ratio

↑ 0.57

ASTS Treynor Ratio

↑ 0.65

Treynor ratio measures excess return per unit of market risk (beta) instead of total volatility. ASTS posted the higher Treynor ratio.

Treynor uses beta vs the S&P 500 (SPY) on shared dates and the average 3-month Treasury rate as the risk-free rate.

Ulcer Index of RKLB and ASTS

RKLB Ulcer Index

17.75%

ASTS Ulcer Index

20.81%

Ulcer Index captures drawdown depth and duration. Lower Ulcer Index means less drawdown pain. RKLB had the lower Ulcer Index (less drawdown pain).

Ulcer Index is computed from each asset's drawdown series over the full lookback window.

Tail Risk & Distribution Shape (1-Year): Rocket Lab USA vs. AST SpaceMobile

This section looks at the shape of daily returns, not just the average. Tail stats are computed per asset on its own daily series (crypto includes weekends). We use daily log returns $\ln\left(\frac{P_t}{P_{t-1}}\right)$ so multi-day moves add cleanly.

Definitions: Value at Risk (VaR), Expected Shortfall, skew, kurtosis, and fat tails.

Metric (1-Year)	RKLB	ASTS
5% VaR (daily log return)	-9.44%	-9.98%
5% Expected Shortfall (CVaR)	-11.00% (worst 13 days)	-11.75% (worst 13 days)
Skew	-0.15	0.01
Excess kurtosis	0.17	-0.10
2σ tail days (down / up)	9 / 4	6 / 9
Worst day	-12.57% (2025-09-16)	-15.17% (2026-02-12)
Best day	+17.69% (2025-12-19)	+18.25% (2025-12-04)

Downside co-moves (2σ) — 1-Year

Computed on shared dates only (n=248). A “2σ downside move” means a shared-close log return more than 2 standard deviations below that asset’s own mean on this shared-date series. Dates below show simple returns (%) for readability.

When ASTS has a big down day, RKLB also does

33.3%

2 / 6 days

When RKLB has a big down day, ASTS also does

22.2%

2 / 9 days

Show downside tail dates

Dates below are shared-date observations. The “Date” is the period end (close). Tail thresholds are computed on log returns, but the table shows simple returns (%) for readability. Returns are computed from the previous shared close to this one (for example, Friday → Monday includes weekend moves).

Days when both RKLB and ASTS had a big down day (2σ)

Date (interval)	RKLB	ASTS
2025-11-20	-9.49%	-12.60%
2025-12-12 → 2025-12-15	-9.89%	-11.59%

Days when RKLB had a big down day

Date (interval)	RKLB	ASTS
2025-05-09	-11.21%	+2.02%
2025-09-03	-11.72%	-7.26%
2025-09-16	-12.57%	-1.32%
2025-11-06	-12.07%	-7.25%
2025-11-20	-9.49%	-12.60%
2025-12-12 → 2025-12-15	-9.89%	-11.59%
2026-02-04	-10.04%	-10.59%
2026-03-18	-11.59%	-5.18%
2026-03-26	-9.52%	-8.54%

Days when ASTS had a big down day

Date (interval)	RKLB	ASTS
2025-04-17 → 2025-04-21	-5.52%	-11.22%
2025-10-31 → 2025-11-03	-2.60%	-11.35%
2025-11-20	-9.49%	-12.60%
2025-12-12 → 2025-12-15	-9.89%	-11.59%
2026-01-07	-2.27%	-12.06%
2026-02-12	-5.19%	-15.17%

Read this as “how ugly the ugly days get”, not as a precise forecast. One-year samples are small, so tail estimates are inherently noisy.

Rocket Lab USA vs AST SpaceMobile Volatility (RKLB vs ASTS)

RKLB Volatility

83.6%

±5.27% daily

ASTS Volatility

98.7%

±6.22% daily

Typical daily swing

RKLB

±5.27%

ASTS

±6.22%

Rocket Lab USA's annualized volatility of 83.6% means it typically moves ±5.27% on any given day.

AST SpaceMobile's annualized volatility of 98.7% means it typically moves ±6.22% on any given day.

ASTS's higher volatility means a wider path to returns — this can be attractive for tactical, shorter-term exposure, while RKLB's smoother profile may better suit long-term allocators seeking steadier growth.

For comparison, the S&P 500 typically has 15-18% annualized volatility, translating to roughly ±1% daily moves. Higher volatility means larger potential gains but also larger potential losses.

Rocket Lab USA vs AST SpaceMobile Performance Over Time

Metric	RKLB	ASTS
30 Days	-5.4%	7.6%
90 Days	-19.8%	-2.8%
180 Days	5.9%	15.7%
1 Year	255.7%	314.2%

Shorter time frames can show different leaders as market conditions change. Consider your investment horizon when comparing performance.

Full Comparison of Rocket Lab USA vs. AST SpaceMobile (1-Year)

Metric	RKLB	ASTS
Total Return	+255.7%	+314.2%
Annualized Volatility	83.6%	98.7%
Sharpe Ratio	1.91	1.91
Sortino Ratio	2.98	3.07
Calmar Ratio	6.07	6.83
Sterling Ratio	12.41	13.06
Treynor Ratio	0.57	0.65
Ulcer Index	17.75%	20.81%
Max Drawdown	-43.0%	-47.0%
Avg Correlation to S&P 500	0.38	0.33
5% VaR (daily log return)	-9.44%	-9.98%
5% Expected Shortfall (CVaR)	-11.00%	-11.75%
Skew	-0.15	0.01
Excess kurtosis	0.17	-0.10
2σ tail days (down / up)	9 / 4	6 / 9

Audit this calculation

Formulas, inputs, and conventions used to compute the metrics on this page.

Inputs & conventions

Shared window for pair metrics: 2025-04-14 → 2026-04-10 (last shared close).
Rolling correlation sample (shared closes): 219 rolling 30-day values (from 248 shared daily returns).
Annualization (days/year): RKLB: 252 days/year; ASTS: 252 days/year.
Risk-free rate: Uses the 3-month U.S. Treasury yield (FRED: DGS3MO), averaged over each asset’s window:

RKLB: 4.17% over 2025-04-14 → 2026-04-10.

ASTS: 4.17% over 2025-04-14 → 2026-04-10.
Volatility drag (rule of thumb): Estimated from annualized volatility (simple returns). For the log-return framing, see Log returns.

RKLB: ≈ -34.9%/yr

ASTS: ≈ -48.7%/yr
Data alignment: No forward fill. Correlation and tail co-moves are computed on shared closes only.
For cross-calendar pairs (e.g., crypto vs stocks), weekend/holiday moves roll into the next shared close.
Return conventions: Volatility/Sharpe/Sortino use simple daily returns. Tail-risk uses daily log returns for distribution stats (but tables show simple returns). Log returns.

Formulas

Daily simple return

r_t = \frac{P_t}{P_{t-1}} - 1

Volatility

\sigma_{ann} = \sigma(r_t)\sqrt{A}

Volatility drag (approx.)

\text{drag} \approx \tfrac{1}{2}\sigma_{ann}^2

Sharpe Ratio

S = \frac{A\,\bar{r} - r_f}{\sigma(r_t)\sqrt{A}}

Sortino Ratio

So = \frac{A\,\bar{r} - r_f}{\sqrt{\mathbb{E}[\min(0,\,r_t - r_f/A)^2]}\,\sqrt{A}}

Maximum Drawdown

MDD = \min_t\left(\frac{P_t}{\max_{s \le t} P_s} - 1\right)

Average Correlation

\rho = \frac{\operatorname{cov}(r^A,\,r^B)}{\sigma_A\,\sigma_B}

Log returns

\ell_t = \ln\left(\frac{P_t}{P_{t-1}}\right)

Notation

$P_t$: Price on day t.
$r_t$: Simple daily return.
$\ell_t$: Log daily return.
$\bar{r}$: Average daily return.
$\sigma(r_t)$: Standard deviation of daily returns.
$A$: Annualization factor (days/year).
$r_f$: Annual risk-free rate.

Rocket Lab USA vs AST SpaceMobile: Frequently Asked Questions

Which has higher volatility: RKLB or ASTS?

ASTS showed higher volatility at 98.7% annualized, compared to 83.6% for RKLB Over the past year. Higher volatility means larger price swings in both directions.

Does RKLB provide diversification when held with ASTS?

RKLB and ASTS are strongly correlated over the past year, with an average correlation of 0.61. This strong correlation limits diversification benefits.

How bad are the worst 5% days for RKLB vs ASTS?

Over the past year, RKLB's 5% VaR was -9.44% and its 5% Expected Shortfall was -11.00% (worst 13 days). ASTS's were -9.98% and -11.75% (worst 13 days).

Do RKLB and ASTS crash together on bad days?

On shared dates (n=248), when ASTS has a 2σ down day, RKLB also does 33.3% (2/6 days). In the other direction, when RKLB has one, ASTS also does 22.2% (2/9 days).

Which has better risk-adjusted returns: RKLB or ASTS?

Both assets showed similar risk-adjusted performance with Sharpe ratios of 1.91 and 1.91 Over the past year.

Can RKLB and ASTS be combined in a portfolio?

Yes, though allocation sizing matters. Their strong correlation provides limited risk reduction since they tend to move together. ASTS's higher volatility (98.7%) means even small allocations can materially impact overall portfolio risk.

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