COHR vs AAOI: Stock Returns, Risk & Volatility (2026)

Q: Which is a better investment: COHR or AAOI?

Over the past year, it depends: AAOI led on total return (AAOI +1238.7% vs COHR +447.7%), but COHR had the higher Sharpe ratio (COHR 2.81 vs AAOI 2.58). On risk, COHR was less volatile (COHR 68.5% vs AAOI 132.9%), COHR had a smaller max drawdown (COHR -26.5% vs AAOI -47.6%), and COHR had less severe losses on the worst 5% of days (Expected Shortfall of COHR -10.01% vs AAOI -14.38%).

Written by Gale Finance Team

Reviewed by Sid Kalla CFA Charterholder

Quick answer

Which is a better investment: COHR or AAOI?

Over the past year, results are mixed (+447.7% vs +1238.7%).

Total Return

COHR +447.7%

AAOI WIN +1238.7%

Sharpe Ratio

COHR WIN 2.81

AAOI 2.58

Annualized Volatility

COHR WIN 68.5%

AAOI 132.9%

Max Drawdown

COHR WIN -26.5%

AAOI -47.6%

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

COHR Total Return

↑ +447.7%

AAOI Total Return

↑ +1238.7%

Relative Performance of COHR vs AAOI (Normalized to 100)

COHR AAOI

Normalized to 100 at start date for comparison

Key Takeaways

Total Return: COHR delivered a +447.7% total return, while AAOI returned +1238.7% over the same period. AAOI outperformed on total returns.
Risk-Adjusted Return (Sharpe Ratio): COHR had a higher Sharpe (2.81 vs 2.58), indicating better risk-adjusted performance.
Volatility (Annualized): AAOI was more volatile, with 132.9% annualized volatility, versus 68.5% for COHR.
Maximum Drawdown: COHR's maximum drawdown was -26.5%, while AAOI experienced a deeper drawdown of -47.6%.
Tail Risk (VaR & Expected Shortfall): At the 5% level (daily log returns), COHR's VaR was -6.25% and its Expected Shortfall (CVaR) was -10.01%; AAOI's were -11.68% and -14.38%. VaR is the cutoff; Expected Shortfall is the average move on the worst days.
Skew & Kurtosis: Skew: COHR -0.56 vs AAOI 0.82. Excess kurtosis: COHR 3.56 vs AAOI 3.38. Negative skew leans downside; higher excess kurtosis means fatter tails.
Tail Days & Extremes: 2σ tail days (down/up): COHR 10/4, AAOI 4/9. Worst day: COHR -19.61% (2025-08-14) vs AAOI -16.39% (2026-03-12). Best day: COHR +18.32% (2025-11-06) vs AAOI +56.88% (2026-02-27).
Risk ratios: Sortino - COHR: 4.42 vs. AAOI: 4.97 , Calmar - COHR: 17.30 vs. AAOI: 26.87 , Sterling - COHR: 25.60 vs. AAOI: 60.34 , Treynor - COHR: 0.70 vs. AAOI: 0.83 , Ulcer Index - COHR: 9.21% vs. AAOI: 16.88%

Coherent Corp. vs Applied Optoelectronics Correlation

0.56 Average Correlation

Coherent Corp. and Applied Optoelectronics are moderately correlated over the past year. With a correlation of 0.56, these assets show moderate co-movement, offering some diversification when held together.

For portfolio construction, this moderate correlation offers some diversification benefit, though the assets still tend to move together during major market moves.

Metric	Value
Current (30-day)	0.62
Average (full period)	0.56
Minimum	0.23
Maximum	0.81

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:

COHR $54,773.78 +447.7%

AAOI $133,866.67 +1238.7%

Difference: $79,092.89 (AAOI ahead)

Coherent Corp. and Applied Optoelectronics: Risk Analysis

Coherent Corp. experienced its maximum drawdown of -26.5% from 2026-03-02 to 2026-03-30. It took 11 days to recover.

Applied Optoelectronics experienced its maximum drawdown of -47.6% from 2025-10-27 to 2025-11-20. It took 32 days to recover.

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

Sharpe Ratio of COHR and AAOI

COHR Sharpe Ratio

↑ 2.81

AAOI Sharpe Ratio

↑ 2.58

Sharpe ratio measures return per unit of risk (volatility). A higher Sharpe indicates better risk-adjusted performance. COHR had a higher Sharpe (2.81 vs 2.58), indicating better 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 COHR and AAOI

COHR Sortino Ratio

↑ 4.42

AAOI Sortino Ratio

↑ 4.97

Sortino ratio measures return per unit of downside risk. Unlike Sharpe, it only counts downside deviation (returns below the target return). AAOI 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: COHR 43.6% vs AAOI 69.0%. 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 COHR and AAOI

COHR Calmar Ratio

↑ 17.30

AAOI Calmar Ratio

↑ 26.87

Calmar ratio compares CAGR to maximum drawdown. Higher Calmar means more return per unit of worst drawdown. AAOI 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 COHR and AAOI

COHR Sterling Ratio

↑ 25.60

AAOI Sterling Ratio

↑ 60.34

Sterling ratio measures excess return per unit of average drawdown (typically drawdowns worse than 10%). AAOI 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 COHR and AAOI

COHR Treynor Ratio

↑ 0.70

AAOI Treynor Ratio

↑ 0.83

Treynor ratio measures excess return per unit of market risk (beta) instead of total volatility. AAOI 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 COHR and AAOI

COHR Ulcer Index

9.21%

AAOI Ulcer Index

16.88%

Ulcer Index captures drawdown depth and duration. Lower Ulcer Index means less drawdown pain. COHR 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): Coherent Corp. vs. Applied Optoelectronics

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)	COHR	AAOI
5% VaR (daily log return)	-6.25%	-11.68%
5% Expected Shortfall (CVaR)	-10.01% (worst 13 days)	-14.38% (worst 13 days)
Skew	-0.56	0.82
Excess kurtosis	3.56	3.38
2σ tail days (down / up)	10 / 4	4 / 9
Worst day	-19.61% (2025-08-14)	-16.39% (2026-03-12)
Best day	+18.32% (2025-11-06)	+56.88% (2026-02-27)

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 AAOI has a big down day, COHR also does

75.0%

3 / 4 days

When COHR has a big down day, AAOI also does

30.0%

3 / 10 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 COHR and AAOI had a big down day (2σ)

Date (interval)	COHR	AAOI
2025-10-10	-9.19%	-16.13%
2026-03-20	-7.96%	-14.11%
2026-03-26	-10.57%	-14.85%

Days when COHR had a big down day

Date (interval)	COHR	AAOI
2025-08-14	-19.61%	-8.73%
2025-10-10	-9.19%	-16.13%
2025-11-13	-10.66%	-12.66%
2025-12-12	-10.16%	-11.73%
2026-01-08	-9.64%	-13.26%
2026-02-04	-7.93%	-13.49%
2026-03-05	-7.64%	+1.43%
2026-03-20	-7.96%	-14.11%
2026-03-26	-10.57%	-14.85%
2026-03-27 → 2026-03-30	-9.79%	-13.26%

Days when AAOI had a big down day

Date (interval)	COHR	AAOI
2025-10-10	-9.19%	-16.13%
2026-03-12	-4.03%	-16.39%
2026-03-20	-7.96%	-14.11%
2026-03-26	-10.57%	-14.85%

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.

Coherent Corp. vs Applied Optoelectronics Volatility (COHR vs AAOI)

COHR Volatility

68.5%

±4.31% daily

AAOI Volatility

132.9%

±8.37% daily

Typical daily swing

COHR

±4.31%

AAOI

±8.37%

Coherent Corp.'s annualized volatility of 68.5% means it typically moves ±4.31% on any given day.

Applied Optoelectronics's annualized volatility of 132.9% means it typically moves ±8.37% on any given day.

AAOI's higher volatility means a wider path to returns — this can be attractive for tactical, shorter-term exposure, while COHR'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.

Coherent Corp. vs Applied Optoelectronics Performance Over Time

Metric	COHR	AAOI
30 Days	22.3%	18.6%
90 Days	72.7%	342.4%
180 Days	176.8%	454.7%
1 Year	447.7%	1238.7%

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

Full Comparison of Coherent Corp. vs. Applied Optoelectronics (1-Year)

Metric	COHR	AAOI
Total Return	+447.7%	+1238.7%
Annualized Volatility	68.5%	132.9%
Sharpe Ratio	2.81	2.58
Sortino Ratio	4.42	4.97
Calmar Ratio	17.30	26.87
Sterling Ratio	25.60	60.34
Treynor Ratio	0.70	0.83
Ulcer Index	9.21%	16.88%
Max Drawdown	-26.5%	-47.6%
Avg Correlation to S&P 500	0.49	0.46
5% VaR (daily log return)	-6.25%	-11.68%
5% Expected Shortfall (CVaR)	-10.01%	-14.38%
Skew	-0.56	0.82
Excess kurtosis	3.56	3.38
2σ tail days (down / up)	10 / 4	4 / 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): COHR: 252 days/year; AAOI: 252 days/year.
Risk-free rate: Uses the 3-month U.S. Treasury yield (FRED: DGS3MO), averaged over each asset’s window:

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

AAOI: 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.

COHR: ≈ -23.5%/yr

AAOI: ≈ -88.3%/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.

Coherent Corp. vs Applied Optoelectronics: Frequently Asked Questions

Which has higher volatility: COHR or AAOI?

AAOI showed higher volatility at 132.9% annualized, compared to 68.5% for COHR Over the past year. Higher volatility means larger price swings in both directions.

Does COHR provide diversification when held with AAOI?

COHR and AAOI are moderately correlated over the past year, with an average correlation of 0.56. This offers some diversification benefit, though they still tend to move together during major market moves.

How bad are the worst 5% days for COHR vs AAOI?

Over the past year, COHR's 5% VaR was -6.25% and its 5% Expected Shortfall was -10.01% (worst 13 days). AAOI's were -11.68% and -14.38% (worst 13 days).

Do COHR and AAOI crash together on bad days?

On shared dates (n=248), when AAOI has a 2σ down day, COHR also does 75.0% (3/4 days). In the other direction, when COHR has one, AAOI also does 30.0% (3/10 days).

Which has better risk-adjusted returns: COHR or AAOI?

COHR showed better risk-adjusted performance with a Sharpe ratio of 2.81 versus AAOI's 2.58 Over the past year.

Can COHR and AAOI be combined in a portfolio?

Yes, though allocation sizing matters. Their moderate correlation offers some diversification benefits. AAOI's higher volatility (132.9%) means even small allocations can materially impact overall portfolio risk.

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