CSTL — Stock Film
STOCK FILMSCENE 1/11CSTL · $32.33
Stock Expert AI presents
CSTL
Castle Biosciences, Inc
~5 min film100% real numbersplain English
WHAT DOES THIS COMPANY DO?
Castle Biosciences, Inc. What it actually does.

Develops diagnostic tests for dermatological cancers. Offers DecisionDx-Melanoma, a test for assessing melanoma metastasis risk. Now — the numbers.

on the stock market since 2019
1,002 employees
$987.7M market value
Revenue last year:
$344.2M
The loss that same year:
$24.2M
For every $1 it earns, the company spends $1.1.

The company is still in the product-building phase: its spending runs above its sales. That only changes once the product starts selling at scale.

THE SALES TREND
Sales are growing, year after year.

Average growth of 38% a year over the last 4 years. Red columns mark years that ended in a loss.

$94.1M
2021
2022
2023
2024
$344.2M
2025
In the vault right now:
$299.5M
DEBT: $36.9M
At this pace, that money lasts about 12.4 years.

At this burn rate the cash pile isn’t the pressing question — for now, time is on the company’s side.

What executives did with their own stock over the last 12 months:
63 buy207 sell

Executive selling isn’t always bad news; people sell for personal reasons too. Still, the thin buying side is worth noting.

INSIDE THE REPORT CARD

We compared this company with its own sector across five subjects.

A score of 50 means class average.

BUSINESS QUALITY
81
very strong

Profit power and business quality lead the class.

FINANCIAL STRENGTH
28
very weak

Clearly below the class average.

VALUATION
64
average

The price isn’t cheap next to earnings — that’s why this grade sits in the middle.

GROWTH
22
very weak

Clearly below the class average.

PRICE MOMENTUM
83
very strong

The stock has been running stronger than the market lately.

WORTH WATCHING

Growth: Sales growth trails the sector average.

Financial Strength: The cash-and-debt balance is thin; the buffer for hard times is slim.

THE FIVE-YEAR JOURNEY
Below the peak, but no collapse.

The stock trades 52% below its peak. The market has trimmed its expectations for the company.

1
THE BRIGHT SIDE · 1/3
The product is selling

Sales run at $344.2M a year. A small number, but proof the product has real buyers.

2
THE BRIGHT SIDE · 2/3
Strong cash, light debt

There is $299.5M in the vault; even if every debt were paid off, $262.6M would remain.

3
THE BRIGHT SIDE · 3/3
Delivers on expectations

It met or beat analyst expectations in 7 of the last 8 quarters — consistency is a promise kept.

1
THE RISKS · 1/2
Running at a loss

A loss of $24.2M against $344.2M in annual sales.

2
THE RISKS · 2/2
Executives lean toward selling

Over the last 12 months, executives reported 207 sells against just 63 buys. Not an alarm bell by itself, but a number worth watching.

FINALE · THE GRADE
D
37 / 100 · MoonshotScore

On our five-subject report card, CSTL sits behind the class. A low grade doesn’t mean “doomed” — it means “big claim, small proof.”

The takeaway: CSTL is a high-risk stock — not yet profitable, and its future rides on its product catching on.

The total grade weighs these five subjects against the sector — it isn’t a simple average of the five.

What would you like to do next?
Open the stock page →

Not covered, because the filings we hold do not carry it: the revenue breakdown.

This was a film — not investment advice.
Data: FMP & company filings
Sep 11, 2026 · stockexpertai.com · Stock Film