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Side-by-side financial comparison of CASTLE BIOSCIENCES INC (CSTL) and RING ENERGY, INC. (REI). Click either name above to swap in a different company.

CASTLE BIOSCIENCES INC is the larger business by last-quarter revenue ($83.7M vs $66.9M, roughly 1.3× RING ENERGY, INC.). On growth, CASTLE BIOSCIENCES INC posted the faster year-over-year revenue change (-4.9% vs -19.8%). Over the past eight quarters, CASTLE BIOSCIENCES INC's revenue compounded faster (-1.9% CAGR vs -15.9%).

Castle Biosciences Inc. is a commercial-stage diagnostic firm that develops and markets proprietary, clinically actionable tests for dermatological conditions such as melanoma and other skin cancers, plus rare diseases. It operates mainly in the U.S. healthcare market, focusing on segments with high unmet need for more accurate diagnostics to guide treatment choices.

Siemens Energy AG is a German publicly traded energy corporation formed through the spin-off of the former Gas and Power division of Siemens, and it includes full ownership of Siemens Gamesa.

CSTL vs REI — Head-to-Head

Bigger by revenue
CSTL
CSTL
1.3× larger
CSTL
$83.7M
$66.9M
REI
Growing faster (revenue YoY)
CSTL
CSTL
+14.9% gap
CSTL
-4.9%
-19.8%
REI
Faster 2-yr revenue CAGR
CSTL
CSTL
Annualised
CSTL
-1.9%
-15.9%
REI

Income Statement — Q1 FY2026 vs Q4 FY2025

Metric
CSTL
CSTL
REI
REI
Revenue
$83.7M
$66.9M
Net Profit
$-14.5M
Gross Margin
Operating Margin
-37.6%
Net Margin
-17.4%
Revenue YoY
-4.9%
-19.8%
Net Profit YoY
43.8%
EPS (diluted)
$-0.49
$-0.07

Green = leading value per metric. Periods may differ when fiscal calendars don't align.

8-Quarter Revenue & Profit Trend

Side-by-side quarterly history. Quarters aligned by calendar period so offset fiscal years line up.

Revenue
CSTL
CSTL
REI
REI
Q1 26
$83.7M
Q4 25
$87.0M
$66.9M
Q3 25
$83.0M
$78.6M
Q2 25
$86.2M
$82.6M
Q1 25
$88.0M
$79.1M
Q4 24
$86.3M
$83.4M
Q3 24
$85.8M
$89.2M
Q2 24
$87.0M
$99.1M
Net Profit
CSTL
CSTL
REI
REI
Q1 26
$-14.5M
Q4 25
Q3 25
$-501.0K
$-51.6M
Q2 25
$4.5M
$20.6M
Q1 25
$-25.8M
$9.1M
Q4 24
Q3 24
$2.3M
$33.9M
Q2 24
$8.9M
$22.4M
Gross Margin
CSTL
CSTL
REI
REI
Q1 26
Q4 25
79.0%
Q3 25
77.5%
Q2 25
79.5%
Q1 25
81.4%
Q4 24
81.3%
Q3 24
81.8%
Q2 24
83.3%
Operating Margin
CSTL
CSTL
REI
REI
Q1 26
Q4 25
-4.4%
-37.6%
Q3 25
-8.2%
-70.0%
Q2 25
-4.9%
28.4%
Q1 25
-31.7%
28.3%
Q4 24
4.7%
28.3%
Q3 24
5.9%
33.4%
Q2 24
5.8%
42.2%
Net Margin
CSTL
CSTL
REI
REI
Q1 26
-17.4%
Q4 25
Q3 25
-0.6%
-65.7%
Q2 25
5.2%
25.0%
Q1 25
-29.4%
11.5%
Q4 24
Q3 24
2.6%
38.0%
Q2 24
10.3%
22.6%
EPS (diluted)
CSTL
CSTL
REI
REI
Q1 26
$-0.49
Q4 25
$-0.06
$-0.07
Q3 25
$-0.02
$-0.25
Q2 25
$0.15
$0.10
Q1 25
$-0.90
$0.05
Q4 24
$0.32
$0.03
Q3 24
$0.08
$0.17
Q2 24
$0.31
$0.11

Balance Sheet & Financial Strength

Snapshot of each company's liquidity, leverage and book value from the latest quarter.

Metric
CSTL
CSTL
REI
REI
Cash + ST InvestmentsLiquidity on hand
$63.8M
$902.9K
Total DebtLower is stronger
$10.1M
Stockholders' EquityBook value
$461.4M
$836.3M
Total Assets
$547.8M
$1.4B
Debt / EquityLower = less leverage
0.02×

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
CSTL
CSTL
REI
REI
Q1 26
$63.8M
Q4 25
$299.5M
$902.9K
Q3 25
$287.5M
$286.9K
Q2 25
$275.9M
Q1 25
$275.2M
$1.1M
Q4 24
$293.1M
$1.9M
Q3 24
$95.0M
Q2 24
$85.6M
$1.2M
Total Debt
CSTL
CSTL
REI
REI
Q1 26
$10.1M
Q4 25
$10.1M
Q3 25
$10.0M
Q2 25
$10.0M
Q1 25
$10.0M
Q4 24
$10.0M
Q3 24
$10.0M
Q2 24
$10.0M
Stockholders' Equity
CSTL
CSTL
REI
REI
Q1 26
$461.4M
Q4 25
$470.9M
$836.3M
Q3 25
$467.0M
$847.7M
Q2 25
$455.4M
$897.9M
Q1 25
$440.3M
$876.0M
Q4 24
$455.8M
$858.6M
Q3 24
$441.1M
$851.3M
Q2 24
$423.9M
$817.4M
Total Assets
CSTL
CSTL
REI
REI
Q1 26
$547.8M
Q4 25
$578.6M
$1.4B
Q3 25
$562.8M
$1.4B
Q2 25
$544.7M
$1.5B
Q1 25
$501.7M
$1.5B
Q4 24
$531.2M
$1.4B
Q3 24
$514.6M
$1.4B
Q2 24
$487.3M
$1.4B
Debt / Equity
CSTL
CSTL
REI
REI
Q1 26
0.02×
Q4 25
0.02×
Q3 25
0.02×
Q2 25
0.02×
Q1 25
0.02×
Q4 24
0.02×
Q3 24
0.02×
Q2 24
0.02×

Cash Flow & Capital Efficiency

How much cash each business actually produces after reinvestment. Cash flow is harder to manipulate than net income.

Metric
CSTL
CSTL
REI
REI
Operating Cash FlowLast quarter
$-22.1M
$44.7M
Free Cash FlowOCF − Capex
FCF MarginFCF / Revenue
Capex IntensityCapex / Revenue
Cash ConversionOCF / Net Profit
TTM Free Cash FlowTrailing 4 quarters

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
CSTL
CSTL
REI
REI
Q1 26
$-22.1M
Q4 25
$26.9M
$44.7M
Q3 25
$22.6M
$44.5M
Q2 25
$20.8M
$33.3M
Q1 25
$-6.0M
$28.4M
Q4 24
$24.4M
$47.3M
Q3 24
$23.3M
$51.3M
Q2 24
$24.0M
$50.6M
Free Cash Flow
CSTL
CSTL
REI
REI
Q1 26
Q4 25
$19.7M
Q3 25
$7.8M
Q2 25
$11.6M
Q1 25
$-10.8M
Q4 24
$16.8M
Q3 24
$17.0M
Q2 24
$18.8M
FCF Margin
CSTL
CSTL
REI
REI
Q1 26
Q4 25
22.7%
Q3 25
9.4%
Q2 25
13.4%
Q1 25
-12.2%
Q4 24
19.5%
Q3 24
19.8%
Q2 24
21.6%
Capex Intensity
CSTL
CSTL
REI
REI
Q1 26
Q4 25
8.3%
Q3 25
17.9%
Q2 25
10.7%
Q1 25
5.4%
Q4 24
8.8%
Q3 24
7.4%
Q2 24
6.0%
Cash Conversion
CSTL
CSTL
REI
REI
Q1 26
Q4 25
Q3 25
Q2 25
4.60×
1.61×
Q1 25
3.11×
Q4 24
Q3 24
10.29×
1.52×
Q2 24
2.69×
2.26×

Financial Flow Comparison

Revenue → gross profit → operating profit → net profit for each company.

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