vs

Side-by-side financial comparison of CASTLE BIOSCIENCES INC (CSTL) and Eos Energy Enterprises, Inc. (EOSE). Click either name above to swap in a different company.

CASTLE BIOSCIENCES INC is the larger business by last-quarter revenue ($83.7M vs $58.0M, roughly 1.4× Eos Energy Enterprises, Inc.). CASTLE BIOSCIENCES INC runs the higher net margin — -17.4% vs -207.7%, a 190.3% gap on every dollar of revenue. On growth, Eos Energy Enterprises, Inc. posted the faster year-over-year revenue change (699.6% vs -4.9%).

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.

Eos Energy Enterprises, Inc. is an energy storage solutions provider that designs, produces and deploys safe long-duration zinc-based battery systems. It serves utility, commercial, industrial and microgrid customers across North America, Europe and Asia, supporting grid stability and renewable energy integration.

CSTL vs EOSE — Head-to-Head

Bigger by revenue
CSTL
CSTL
1.4× larger
CSTL
$83.7M
$58.0M
EOSE
Growing faster (revenue YoY)
EOSE
EOSE
+704.5% gap
EOSE
699.6%
-4.9%
CSTL
Higher net margin
CSTL
CSTL
190.3% more per $
CSTL
-17.4%
-207.7%
EOSE

Income Statement — Q1 FY2026 vs Q4 FY2025

Metric
CSTL
CSTL
EOSE
EOSE
Revenue
$83.7M
$58.0M
Net Profit
$-14.5M
$-120.5M
Gross Margin
-93.8%
Operating Margin
-140.1%
Net Margin
-17.4%
-207.7%
Revenue YoY
-4.9%
699.6%
Net Profit YoY
43.8%
55.1%
EPS (diluted)
$-0.49
$-0.53

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
EOSE
EOSE
Q1 26
$83.7M
Q4 25
$87.0M
$58.0M
Q3 25
$83.0M
$30.5M
Q2 25
$86.2M
$15.2M
Q1 25
$88.0M
$10.5M
Q4 24
$86.3M
$7.3M
Q3 24
$85.8M
Q2 24
$87.0M
Net Profit
CSTL
CSTL
EOSE
EOSE
Q1 26
$-14.5M
Q4 25
$-120.5M
Q3 25
$-501.0K
$-641.4M
Q2 25
$4.5M
$-222.9M
Q1 25
$-25.8M
$15.1M
Q4 24
$-268.1M
Q3 24
$2.3M
Q2 24
$8.9M
Gross Margin
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
79.0%
-93.8%
Q3 25
77.5%
-111.2%
Q2 25
79.5%
-203.2%
Q1 25
81.4%
-234.7%
Q4 24
81.3%
-324.0%
Q3 24
81.8%
Q2 24
83.3%
Operating Margin
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
-4.4%
-140.1%
Q3 25
-8.2%
-200.6%
Q2 25
-4.9%
-419.1%
Q1 25
-31.7%
-506.2%
Q4 24
4.7%
-712.8%
Q3 24
5.9%
Q2 24
5.8%
Net Margin
CSTL
CSTL
EOSE
EOSE
Q1 26
-17.4%
Q4 25
-207.7%
Q3 25
-0.6%
-2102.1%
Q2 25
5.2%
-1463.2%
Q1 25
-29.4%
144.7%
Q4 24
-3696.7%
Q3 24
2.6%
Q2 24
10.3%
EPS (diluted)
CSTL
CSTL
EOSE
EOSE
Q1 26
$-0.49
Q4 25
$-0.06
$-0.53
Q3 25
$-0.02
$-4.91
Q2 25
$0.15
$-1.05
Q1 25
$-0.90
$-0.20
Q4 24
$0.32
$-2.30
Q3 24
$0.08
Q2 24
$0.31

Balance Sheet & Financial Strength

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

Metric
CSTL
CSTL
EOSE
EOSE
Cash + ST InvestmentsLiquidity on hand
$63.8M
$568.0M
Total DebtLower is stronger
$10.1M
$813.3M
Stockholders' EquityBook value
$461.4M
$-2.2B
Total Assets
$547.8M
$885.2M
Debt / EquityLower = less leverage
0.02×

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
CSTL
CSTL
EOSE
EOSE
Q1 26
$63.8M
Q4 25
$299.5M
$568.0M
Q3 25
$287.5M
$58.7M
Q2 25
$275.9M
$120.2M
Q1 25
$275.2M
$82.6M
Q4 24
$293.1M
$74.3M
Q3 24
$95.0M
Q2 24
$85.6M
Total Debt
CSTL
CSTL
EOSE
EOSE
Q1 26
$10.1M
Q4 25
$10.1M
$813.3M
Q3 25
$10.0M
$448.5M
Q2 25
$10.0M
$445.3M
Q1 25
$10.0M
$325.5M
Q4 24
$10.0M
$316.9M
Q3 24
$10.0M
Q2 24
$10.0M
Stockholders' Equity
CSTL
CSTL
EOSE
EOSE
Q1 26
$461.4M
Q4 25
$470.9M
$-2.2B
Q3 25
$467.0M
$-2.3B
Q2 25
$455.4M
$-1.1B
Q1 25
$440.3M
$-942.2M
Q4 24
$455.8M
$-1.1B
Q3 24
$441.1M
Q2 24
$423.9M
Total Assets
CSTL
CSTL
EOSE
EOSE
Q1 26
$547.8M
Q4 25
$578.6M
$885.2M
Q3 25
$562.8M
$328.2M
Q2 25
$544.7M
$361.0M
Q1 25
$501.7M
$263.3M
Q4 24
$531.2M
$260.3M
Q3 24
$514.6M
Q2 24
$487.3M
Debt / Equity
CSTL
CSTL
EOSE
EOSE
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
EOSE
EOSE
Operating Cash FlowLast quarter
$-22.1M
$-50.3M
Free Cash FlowOCF − Capex
$-75.2M
FCF MarginFCF / Revenue
-129.7%
Capex IntensityCapex / Revenue
43.1%
Cash ConversionOCF / Net Profit
TTM Free Cash FlowTrailing 4 quarters
$-265.0M

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
CSTL
CSTL
EOSE
EOSE
Q1 26
$-22.1M
Q4 25
$26.9M
$-50.3M
Q3 25
$22.6M
$-65.9M
Q2 25
$20.8M
$-66.1M
Q1 25
$-6.0M
$-28.9M
Q4 24
$24.4M
$-42.7M
Q3 24
$23.3M
Q2 24
$24.0M
Free Cash Flow
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
$19.7M
$-75.2M
Q3 25
$7.8M
$-82.7M
Q2 25
$11.6M
$-73.2M
Q1 25
$-10.8M
$-33.8M
Q4 24
$16.8M
$-55.8M
Q3 24
$17.0M
Q2 24
$18.8M
FCF Margin
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
22.7%
-129.7%
Q3 25
9.4%
-271.1%
Q2 25
13.4%
-480.2%
Q1 25
-12.2%
-323.6%
Q4 24
19.5%
-769.1%
Q3 24
19.8%
Q2 24
21.6%
Capex Intensity
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
8.3%
43.1%
Q3 25
17.9%
55.2%
Q2 25
10.7%
46.2%
Q1 25
5.4%
47.0%
Q4 24
8.8%
180.6%
Q3 24
7.4%
Q2 24
6.0%
Cash Conversion
CSTL
CSTL
EOSE
EOSE
Q1 26
Q4 25
Q3 25
Q2 25
4.60×
Q1 25
-1.91×
Q4 24
Q3 24
10.29×
Q2 24
2.69×

Financial Flow Comparison

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

Related Comparisons