CSTL vs. EXEL

Last updated Jun 4, 2026

CSTL (Castle Biosciences, Inc.) and EXEL (Exelixis, Inc.) are both stocks. Both are in the Healthcare sector — CSTL in Diagnostics & Research, EXEL in Biotechnology. Over the past 5 years, CSTL returned -20.27%/yr vs 18.19%/yr for EXEL. At a 0.24 correlation, their price movements are largely independent.

Performance

CSTL vs. EXEL - Performance Comparison

The chart below illustrates the hypothetical performance of a $10,000 investment in Castle Biosciences, Inc. (CSTL) and Exelixis, Inc. (EXEL). The values are adjusted to include any dividend payments, if applicable.

Returns By Period

In the year-to-date period, CSTL achieves a -47.58% return, which is significantly lower than EXEL's 17.73% return.

CSTL

• 1D: 3.45%
• 1M: -20.10%
• YTD: -47.58%
• 6M: -48.26%
• 1Y: 22.02%
• 3Y*: -3.56%
• 5Y*: -20.27%
• 10Y*: —

EXEL

• 1D: 6.30%
• 1M: 16.82%
• YTD: 17.73%
• 6M: 17.25%
• 1Y: 20.93%
• 3Y*: 39.06%
• 5Y*: 18.19%
• 10Y*: 22.85%

*Multi-year figures are annualized to reflect compound growth (CAGR)

CSTL vs. EXEL - Yearly Performance Comparison

	2026 (YTD)	2025	2024	2023	2022	2021	2020	2019
CSTL Castle Biosciences, Inc.	-47.58%	45.97%	23.49%	-8.33%	-45.09%	-36.16%	95.37%	60.61%
EXEL Exelixis, Inc.	17.73%	31.62%	38.81%	49.56%	-12.25%	-8.92%	13.90%	-14.59%

Correlation

The correlation between CSTL and EXEL is 0.22, which is low. Their price movements are largely independent, making them effective diversification partners.

	Correlation
Correlation (1Y) Calculated over the trailing 1-year period	0.22
Correlation (3Y) Calculated over the trailing 3-year period	0.20
Correlation (5Y) Calculated over the trailing 5-year period	0.28
Correlation (All Time) Calculated using the full available price history since Jul 26, 2019	0.24

Fundamentals

Market Cap CSTL : $609.44M EXEL : $13.79B
EPS CSTL : -$0.44 EXEL : $3.00
PS Ratio CSTL : 1.77 EXEL : 6.04
PB Ratio CSTL : 1.32 EXEL : 7.13
Total Revenue (TTM) CSTL : $339.92M EXEL : $2.38B
Gross Profit (TTM) CSTL : $164.74M EXEL : $1.70B
EBITDA (TTM) CSTL : $9.62M EXEL : $991.79M

Return for Risk

CSTL vs. EXEL — Risk / Return Rank

Compare risk-adjusted metric ranks to identify better-performing investments over the past 12 months.

CSTL

CSTL Risk / Return Rank: 53
CSTL Sharpe Ratio Rank: 54
CSTL Sortino Ratio Rank: 54
CSTL Omega Ratio Rank: 55
CSTL Calmar Ratio Rank: 50
CSTL Martin Ratio Rank: 51

EXEL

EXEL Risk / Return Rank: 56
EXEL Sharpe Ratio Rank: 58
EXEL Sortino Ratio Rank: 52
EXEL Omega Ratio Rank: 54
EXEL Calmar Ratio Rank: 59
EXEL Martin Ratio Rank: 59

The rank (0–100) shows how this investment's returns compare to the risk taken. Higher = better. Based on the past 12 months of data, combining Sharpe, Sortino, and other metrics used by quantitative funds and institutional investors.

CSTL vs. EXEL - Risk-Adjusted Trends Comparison

This table presents a comparison of risk-adjusted performance metrics for Castle Biosciences, Inc. (CSTL) and Exelixis, Inc. (EXEL). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.

	CSTL	EXEL	Difference
Sharpe ratio Return per unit of total volatility	0.35	0.52	-0.17
Sortino ratio Return per unit of downside risk	0.99	0.94	+0.05
Omega ratio Gain probability vs. loss probability	1.14	1.14	0.00
Calmar ratio Return relative to maximum drawdown	0.38	0.84	-0.45
Martin ratio Return relative to average drawdown	0.88	2.01	-1.13
Data is calculated on a 1-year rolling basis and updated daily. The trend shows the change in the indicator over the past month.

CSTL vs. EXEL - Sharpe Ratio Comparison

The current CSTL Sharpe Ratio is 0.35, which is lower than the EXEL Sharpe Ratio of 0.52. The chart below compares the historical Sharpe Ratios of CSTL and EXEL, calculated using daily returns over the previous 12 months. A higher Sharpe Ratio indicates better risk-adjusted performance relative to the risk-free rate.

Sharpe Ratios by Period

	CSTL	EXEL	Difference
Sharpe Ratio (1Y) Calculated over the trailing 1-year period	0.35	0.52	-0.17
Sharpe Ratio (5Y) Calculated over the trailing 5-year period	-0.27	0.49	-0.77
Sharpe Ratio (10Y) Calculated over the trailing 10-year period	—	0.51	—
Sharpe Ratio (All Time) Calculated using the full available price history	-0.01	0.08	-0.09

Drawdowns

CSTL vs. EXEL - Drawdown Comparison

The maximum CSTL drawdown since its inception was -88.02%, smaller than the maximum EXEL drawdown of -97.38%. Use the drawdown chart below to compare losses from any high point for CSTL and EXEL.

Drawdown Indicators

	CSTL	EXEL	Difference
Max Drawdown Largest peak-to-trough decline	-88.02%	-97.38%	+9.36%
Max Drawdown (1Y) Largest decline over 1 year	-57.83%	-25.16%	-32.67%
Max Drawdown (3Y) Largest decline over 3 years	-57.83%	-25.34%	-32.49%
Max Drawdown (5Y) Largest decline over 5 years	-84.97%	-36.12%	-48.85%
Max Drawdown (10Y) Largest decline over 10 years	—	-57.20%	—
Current Drawdown Current decline from peak	-79.05%	0.00%	-79.05%
Average Drawdown Average peak-to-trough decline	-54.66%	-71.11%	+16.45%
Ulcer Index Depth and duration of drawdowns from previous peaks	24.98%	10.44%	+14.54%

Volatility

CSTL vs. EXEL - Volatility Comparison

Castle Biosciences, Inc. (CSTL) has a higher volatility of 30.06% compared to Exelixis, Inc. (EXEL) at 15.21%. This indicates that CSTL's price experiences larger fluctuations and is considered to be riskier than EXEL based on this measure. The chart below showcases a comparison of their rolling one-month volatility.

Volatility by Period

	CSTL	EXEL	Difference
Volatility (1M) Calculated over the trailing 1-month period	30.06%	15.21%	+14.85%
Volatility (6M) Calculated over the trailing 6-month period	41.23%	25.87%	+15.36%
Volatility (1Y) Calculated over the trailing 1-year period	63.45%	40.23%	+23.22%
Volatility (5Y) Calculated over the trailing 5-year period, annualized	74.24%	37.16%	+37.08%
Volatility (10Y) Calculated over the trailing 10-year period, annualized	74.36%	44.61%	+29.75%

Dividends

CSTL vs. EXEL - Dividend Comparison

Neither CSTL nor EXEL has paid dividends to shareholders.

Tickers have no history of dividend payments

Financials

CSTL vs. EXEL - Profitability Comparison

The chart below illustrates the profitability comparison between Castle Biosciences, Inc. and Exelixis, Inc. over time, highlighting three key metrics: Gross Profit Margin, Operating Margin, and Net Profit Margin.

CSTL - Gross Margin

Gross margin is calculated as gross profit divided by revenue. For the three months ending on Jun 2026, Castle Biosciences, Inc. reported a gross profit of 0.00 and revenue of 83.68M. Therefore, the gross margin over that period was 0.0%.

EXEL - Gross Margin

Gross margin is calculated as gross profit divided by revenue. For the three months ending on Jun 2026, Exelixis, Inc. reported a gross profit of 0.00 and revenue of 610.81M. Therefore, the gross margin over that period was 0.0%.

CSTL - Operating Margin

Operating margin is calculated as operating income divided by revenue. For the three months ending on Jun 2026, Castle Biosciences, Inc. reported an operating income of 0.00 and revenue of 83.68M, resulting in an operating margin of 0.0%.

EXEL - Operating Margin

Operating margin is calculated as operating income divided by revenue. For the three months ending on Jun 2026, Exelixis, Inc. reported an operating income of 251.34M and revenue of 610.81M, resulting in an operating margin of 41.2%.

CSTL - Net Margin

Net margin is calculated as net income divided by revenue. For the three months ending on Jun 2026, Castle Biosciences, Inc. reported a net income of -14.52M and revenue of 83.68M, resulting in a net margin of -17.4%.

EXEL - Net Margin

Net margin is calculated as net income divided by revenue. For the three months ending on Jun 2026, Exelixis, Inc. reported a net income of 210.47M and revenue of 610.81M, resulting in a net margin of 34.5%.

Frequently Asked Questions

Can I hold both CSTL and EXEL in my portfolio?

CSTL and EXEL have a correlation of 0.22, meaning they provide meaningful diversification benefit when combined. Depending on your allocation goals, holding both could reduce overall portfolio risk.

Which is riskier, CSTL or EXEL?

CSTL has higher volatility (30.06%) compared to EXEL (15.21%). In terms of maximum drawdown, CSTL dropped -88.02% vs EXEL's -97.38%.

Which has better risk-adjusted returns?

EXEL currently has the higher Sharpe Ratio (0.52 vs 0.35), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.