Castle Biosciences Inc.
CSTL evidence brief
What we can confirm
What it means
What to watch
Prepared research question
What matters most for CSTL—catalysts, financial risk and supporting evidence?
Traceable citations · Unknowns marked
BioSniper AI · CSTL
Castle Biosciences Inc. is a diagnostics company focused on providing genomic tests for dermatologic cancers, with a pipeline that includes gene therapies for rare diseases.
Key risk: Medicare coverage loss
BioSniper Score
Based on 4 of 6 signals
Financial data as of Jun 30, 2026.
Tracking 3 clinical trials · 2 catalysts for Castle Biosciences Inc..
Castle Biosciences Inc. is a diagnostics company focused on providing genomic tests for dermatologic cancers, with a pipeline that includes gene therapies for rare diseases.
- Cash & equivalents of $62.1M as of 2026-06-30 [sec].
- Total revenue of $103.5M as of 2026-06-30 [sec].
- Net loss of $2.1M as of 2026-06-30 [sec].
- Shareholders' equity of $470.9M as of 2026-06-30 [sec].
- Total debt of $13.0M as of 2026-06-30 [sec].
What works
- The company has a portfolio of commercial products generating revenue, with total revenue of $103.5M as of 2026-06-30 [sec].
- Management believes existing cash, marketable securities, and anticipated product sales will fund operations for at least the next 12 months [sec_mda · as of 2026-07-30].
- The company is investing in R&D and clinical studies to support current and future product candidates, indicating a commitment to pipeline growth [sec_mda · as of 2026-07-30].
What to weigh
- The company lost Medicare coverage for its DecisionDx-SCC test in April 2025, which has reduced revenues and cash inflows, with further reductions expected unless reconsideration requests are approved [sec_mda · as of 2026-02-26].
- Net income may fluctuate significantly from period to period, and the company expects expenses to increase substantially over time as it invests in commercialization and development activities [sec_mda · as of 2026-07-30].
- The company's ability to maintain profitability heavily depends on maintaining Medicare coverage for its marketed products and successful commercialization of future products [sec_mda · as of 2026-02-26].
From the filings
Quoted directly from source documents.
Management expects existing cash and product sales to fund operations for at least 12 months.
“We believe that our existing cash and cash equivalents, marketable investment securities and anticipated cash generated from the sale of our commercial products will be sufficient to fund our operations for at least the next 12 months.”
SEC MD&A · May 6, 2026
Net income may fluctuate significantly and expenses are expected to increase.
“Our net (loss) income may fluctuate significantly from period to period, depending on the timing of our planned development activities, the growth of our sales and marketing activities and the timing of revenue recognition under ASC 606. We expect our expenses will increase substantially over time as we: • execute clinical studies to generate evidence supporting our current and future product candidates; • execute our commercialization strategy for our current”
SEC MD&A · July 30, 2026
Catalyst timeline
- 2037-07-01 · Phase3_Topline · fcx-007 — Phase 3 Topline: A Pivotal Phase 3 Study of FCX-007 (Genetically-Modified Autologous Human Dermal Fibroblasts) for Re — Topline results from a pivotal Phase 3 study of FCX-007, a gene therapy for a rare disease, are expected; data will inform potential regulatory submission.
- 2042-02-01 · Phase3_Topline — Phase 3 Topline: Evaluation of Dabocemagene Autoficel (D-Fi; FCX-007; Genetically Modified Autologous Human Dermal Fi — Topline results from a Phase 3 study evaluating dabocemagene autoficel (FCX-007) are expected; this is a later-stage readout for the same gene therapy candidate.
Risks & what to watch (4)›
Key risks
- Medicare coverage loss — Loss of Medicare coverage for DecisionDx-SCC test in April 2025 has reduced revenues and cash inflows; further reductions expected unless reconsideration requests are approved [sec_mda · as of 2026-02-26].
- Profitability dependence — Ability to maintain profitability heavily depends on maintaining Medicare coverage for marketed products and successful commercialization of future products [sec_mda · as of 2026-02-26].
- Expense growth — Expenses are expected to increase substantially over time as the company invests in clinical studies, commercialization, and pipeline development [sec_mda · as of 2026-07-30].
- Cash runway uncertainty — Cash runway estimates are based on assumptions that may prove wrong, potentially depleting capital resources sooner than expected [sec_mda · as of 2026-07-30].
What to watch
- Outcome of reconsideration requests for Medicare coverage of DecisionDx-SCC test [sec_mda · as of 2026-02-26].
- Progress and results of clinical studies for pipeline products, including gene therapy candidates [sec_mda · as of 2026-07-30].
- Revenue trends from commercial products and ability to maintain or grow market access [sec_mda · as of 2026-07-30].
Sources: SEC MD&A · Generated August 29, 2026 · How we verify sources →
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Evidence & data
Score breakdownBased on 4 of 6 signals · derived from public data
No clinical pipeline tracked — this score reflects financial & catalyst signals only.
Profitable (positive operating cash flow)
D/E 0.19 · 0% dilution
No tracked pipeline phase
No tracked pipeline candidates
2 upcoming, next in ~3958d
0 buys · 148 sells (180d)
Catalysts
Regulatory
Financials
Institutional Holdings
Source: SEC Form 13F · as of Mar 2026Institutional holders
185
Total value held
$633.3M
| Holder | Shares | Value |
|---|---|---|
| blackrock, inc. | 2,982,946 | $73.2M |
| rtw investments, lp | 2,758,335 | $67.7M |
| vanguard capital management llc | 2,355,044 | $57.8M |
| principal financial group inc | 1,769,877 | $43.5M |
| dimensional fund advisors lp | 1,039,761 | $25.5M |
| summit partners public asset management, llc | 940,685 | $23.1M |
| vanguard portfolio management llc | 861,771 | $21.2M |
| state street corp | 769,079 | $18.9M |
| geode capital management, llc | 728,100 | $17.9M |
| aigh capital management llc | 590,601 | $14.5M |
Showing top 10 of 185 institutional holders of Castle Biosciences Inc.. Open the full 13F history after sign-in.
Short Interest
as of May 20, 2026- % of float
- 4.8%
- Days to cover
- 4.8
- Shares short
- 1,429,016
- Daily short volume
- -
Short percent of float and days-to-cover reflect reported short positioning. Daily short volume is the exchange-reported short share of a single day's trading volume and is noisier. See the most-shorted biotech ranking →
CSTL short interestGovernance
Frequently asked questions
What is the AI investment thesis for Castle Biosciences Inc.?
Castle Biosciences Inc. is a diagnostics company focused on providing genomic tests for dermatologic cancers, with a pipeline that includes gene therapies for rare diseases.
What is Castle Biosciences Inc.'s next catalyst?
Castle Biosciences Inc.'s next tracked catalyst is a Phase3_Topline event — "Phase 3 Topline: A Pivotal Phase 3 Study of FCX-007 (Genetically-Modified Autologous Human Dermal Fibroblasts) for Re" — expected July 1, 2037.
Who is the CEO of Castle Biosciences Inc.?
Mr. Derek J. Maetzold is the chief executive officer of Castle Biosciences Inc. (CSTL).
Where is Castle Biosciences Inc. headquartered?
Castle Biosciences Inc. (CSTL) is headquartered in Friendswood, TX, United States.
The AI overview and BioSniper Score are neutral, data-derived signals built from public SEC filings, ClinicalTrials.gov and FDA records — not investment advice.