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Side-by-side financial comparison of C3.ai, Inc. (AI) and CASTLE BIOSCIENCES INC (CSTL). Click either name above to swap in a different company.

CASTLE BIOSCIENCES INC is the larger business by last-quarter revenue ($83.7M vs $75.1M, roughly 1.1× C3.ai, Inc.). CASTLE BIOSCIENCES INC runs the higher net margin — -17.4% vs -139.3%, a 121.9% gap on every dollar of revenue. On growth, CASTLE BIOSCIENCES INC posted the faster year-over-year revenue change (-4.9% vs -20.3%). Over the past eight quarters, CASTLE BIOSCIENCES INC's revenue compounded faster (-1.9% CAGR vs -2.1%).

C3.ai, Inc. is a leading enterprise artificial intelligence software provider that develops and delivers scalable AI applications, platform tools, and industry-specific solutions for clients across sectors including manufacturing, energy, financial services, healthcare and public sector. Its offerings help organizations optimize operations, reduce costs, mitigate risks, and realize data-driven decision making.

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.

AI vs CSTL — Head-to-Head

Bigger by revenue
CSTL
CSTL
1.1× larger
CSTL
$83.7M
$75.1M
AI
Growing faster (revenue YoY)
CSTL
CSTL
+15.4% gap
CSTL
-4.9%
-20.3%
AI
Higher net margin
CSTL
CSTL
121.9% more per $
CSTL
-17.4%
-139.3%
AI
Faster 2-yr revenue CAGR
CSTL
CSTL
Annualised
CSTL
-1.9%
-2.1%
AI

Income Statement — Q2 FY2026 vs Q1 FY2026

Metric
AI
AI
CSTL
CSTL
Revenue
$75.1M
$83.7M
Net Profit
$-104.7M
$-14.5M
Gross Margin
40.4%
Operating Margin
-149.2%
Net Margin
-139.3%
-17.4%
Revenue YoY
-20.3%
-4.9%
Net Profit YoY
-58.7%
43.8%
EPS (diluted)
$-0.75
$-0.49

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
AI
AI
CSTL
CSTL
Q1 26
$83.7M
Q4 25
$75.1M
$87.0M
Q3 25
$70.3M
$83.0M
Q2 25
$108.7M
$86.2M
Q1 25
$98.8M
$88.0M
Q4 24
$94.3M
$86.3M
Q3 24
$87.2M
$85.8M
Q2 24
$86.6M
$87.0M
Net Profit
AI
AI
CSTL
CSTL
Q1 26
$-14.5M
Q4 25
$-104.7M
Q3 25
$-116.8M
$-501.0K
Q2 25
$-79.7M
$4.5M
Q1 25
$-80.2M
$-25.8M
Q4 24
$-66.0M
Q3 24
$-62.8M
$2.3M
Q2 24
$-72.9M
$8.9M
Gross Margin
AI
AI
CSTL
CSTL
Q1 26
Q4 25
40.4%
79.0%
Q3 25
37.6%
77.5%
Q2 25
62.1%
79.5%
Q1 25
59.1%
81.4%
Q4 24
61.3%
81.3%
Q3 24
59.8%
81.8%
Q2 24
59.6%
83.3%
Operating Margin
AI
AI
CSTL
CSTL
Q1 26
Q4 25
-149.2%
-4.4%
Q3 25
-177.7%
-8.2%
Q2 25
-81.8%
-4.9%
Q1 25
-88.7%
-31.7%
Q4 24
-79.8%
4.7%
Q3 24
-83.2%
5.9%
Q2 24
-95.1%
5.8%
Net Margin
AI
AI
CSTL
CSTL
Q1 26
-17.4%
Q4 25
-139.3%
Q3 25
-166.2%
-0.6%
Q2 25
-73.3%
5.2%
Q1 25
-81.2%
-29.4%
Q4 24
-69.9%
Q3 24
-72.0%
2.6%
Q2 24
-84.2%
10.3%
EPS (diluted)
AI
AI
CSTL
CSTL
Q1 26
$-0.49
Q4 25
$-0.75
$-0.06
Q3 25
$-0.86
$-0.02
Q2 25
$-0.60
$0.15
Q1 25
$-0.62
$-0.90
Q4 24
$-0.52
$0.32
Q3 24
$-0.50
$0.08
Q2 24
$-0.59
$0.31

Balance Sheet & Financial Strength

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

Metric
AI
AI
CSTL
CSTL
Cash + ST InvestmentsLiquidity on hand
$675.0M
$63.8M
Total DebtLower is stronger
$10.1M
Stockholders' EquityBook value
$771.9M
$461.4M
Total Assets
$961.3M
$547.8M
Debt / EquityLower = less leverage
0.02×

8-quarter trend — quarters aligned by calendar period.

Cash + ST Investments
AI
AI
CSTL
CSTL
Q1 26
$63.8M
Q4 25
$675.0M
$299.5M
Q3 25
$711.9M
$287.5M
Q2 25
$742.7M
$275.9M
Q1 25
$724.3M
$275.2M
Q4 24
$730.4M
$293.1M
Q3 24
$762.5M
$95.0M
Q2 24
$750.4M
$85.6M
Total Debt
AI
AI
CSTL
CSTL
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
AI
AI
CSTL
CSTL
Q1 26
$461.4M
Q4 25
$771.9M
$470.9M
Q3 25
$798.8M
$467.0M
Q2 25
$838.3M
$455.4M
Q1 25
$860.2M
$440.3M
Q4 24
$859.0M
$455.8M
Q3 24
$874.9M
$441.1M
Q2 24
$873.4M
$423.9M
Total Assets
AI
AI
CSTL
CSTL
Q1 26
$547.8M
Q4 25
$961.3M
$578.6M
Q3 25
$968.7M
$562.8M
Q2 25
$1.0B
$544.7M
Q1 25
$1.1B
$501.7M
Q4 24
$1.0B
$531.2M
Q3 24
$1.1B
$514.6M
Q2 24
$1.0B
$487.3M
Debt / Equity
AI
AI
CSTL
CSTL
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
AI
AI
CSTL
CSTL
Operating Cash FlowLast quarter
$-46.5M
$-22.1M
Free Cash FlowOCF − Capex
$-46.9M
FCF MarginFCF / Revenue
-62.4%
Capex IntensityCapex / Revenue
0.5%
Cash ConversionOCF / Net Profit
TTM Free Cash FlowTrailing 4 quarters
$-93.2M

8-quarter trend — quarters aligned by calendar period.

Operating Cash Flow
AI
AI
CSTL
CSTL
Q1 26
$-22.1M
Q4 25
$-46.5M
$26.9M
Q3 25
$-33.5M
$22.6M
Q2 25
$11.3M
$20.8M
Q1 25
$-22.0M
$-6.0M
Q4 24
$-38.7M
$24.4M
Q3 24
$8.0M
$23.3M
Q2 24
$21.3M
$24.0M
Free Cash Flow
AI
AI
CSTL
CSTL
Q1 26
Q4 25
$-46.9M
$19.7M
Q3 25
$-34.3M
$7.8M
Q2 25
$10.3M
$11.6M
Q1 25
$-22.4M
$-10.8M
Q4 24
$-39.5M
$16.8M
Q3 24
$7.1M
$17.0M
Q2 24
$18.8M
$18.8M
FCF Margin
AI
AI
CSTL
CSTL
Q1 26
Q4 25
-62.4%
22.7%
Q3 25
-48.8%
9.4%
Q2 25
9.5%
13.4%
Q1 25
-22.7%
-12.2%
Q4 24
-41.9%
19.5%
Q3 24
8.2%
19.8%
Q2 24
21.7%
21.6%
Capex Intensity
AI
AI
CSTL
CSTL
Q1 26
Q4 25
0.5%
8.3%
Q3 25
1.1%
17.9%
Q2 25
0.9%
10.7%
Q1 25
0.4%
5.4%
Q4 24
0.9%
8.8%
Q3 24
1.1%
7.4%
Q2 24
2.9%
6.0%
Cash Conversion
AI
AI
CSTL
CSTL
Q1 26
Q4 25
Q3 25
Q2 25
4.60×
Q1 25
Q4 24
Q3 24
10.29×
Q2 24
2.69×

Financial Flow Comparison

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

Revenue Breakdown by Segment

AI
AI

License And Service$70.2M93%
Professional Services$4.9M7%

CSTL
CSTL

Segment breakdown not available.

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