Castle Biosciences (CSTL) vs Exagen (XGN)
Head-to-head comparison of performance, valuation, growth, profitability and dividends. Prices delayed 15 minutes; data as of Oct 8, 2026.
Summary
Castle Biosciences (CSTL) has outperformed Exagen (XGN) over the past year, gaining 44.0% versus a loss of 24.3%. Over five years, XGN leads with a -34.3% price change compared with -48.1% for CSTL. Castle Biosciences is the larger company by market cap ($1.03 billion vs $197.9 million), about 5.2 times the size.
Summary generated from market data by MetaCap's automated system. Methodology
Relative performance
Percent change in share price from the first common trading day shown; excludes dividends.
Head-to-head
| Metric | CSTL | XGN |
|---|---|---|
| Share price | $33.71 | $8.17 |
| Market cap | $1.03B | $197.92M |
| 1-day change | +2.15% | -1.57% |
| YTD return | -15.17% | +36.51% |
| 1-year return | +43.98% | -24.27% |
| 5-year return | -48.10% | -34.28% |
| EPS (TTM) | $-0.64 | $-0.81 |
| Dividend yield | 0.00% | 0.00% |
| Annual dividend | $0.00 | $0.00 |
| 52-week high | $44.28 | $12.23 |
| 52-week low | $17.72 | $2.59 |
| Distance from 52-week high | -23.87% | -33.20% |
| Analyst consensus | strong_buy | none |
| Avg. price target upside | +33.82% | +24.11% |
| Average volume | 401.17K | 328.42K |
| Shares outstanding | 30.55M | 24.23M |
| Employees | 1,002 | 216 |
| Sector | Health Care | Health Care |
| Industry | Medical Specialities | Medical Specialities |
Highlighted cells mark the higher value for growth, returns, margins and yield, and the lower value for P/E ratios. Highlighting is a mechanical comparison, not a recommendation.
Key differences
- Castle Biosciences is about 5.2 times larger than Exagen by market value ($1.03B vs $197.92M).
- CSTL has outperformed XGN by 68.2 percentage points over the past year.
About Castle Biosciences
CSTL stock →Castle Biosciences, Inc., a molecular diagnostics company, provides test solutions for the diagnosis and treatment of dermatologic cancers, Barrett's esophagus (BE), atopic dermatitis (AD), and uveal melanoma. The company offers DecisionDx-Melanoma, a risk stratification gene expression profile (GEP) test that predicts the likelihood of a positive sentinel lymph node and the risk of metastasis for patients with invasive cutaneous melanoma; TissueCypher, a risk stratification spatialomics test to predict future development of high-grade dysplasia and/or esophageal cancer in patients with non-dysplastic, indefinite dysplasia, and low-grade dysplasia BE; AdvanceAD-Tx, a non-invasive GEP test which is designed to guide systemic treatment selection for patients aged 12 years and older with moderateto-severe AD; DecisionDx-SCC, a GEP test for cutaneous squamous cell carcinoma; and MyPath Melanoma, a diagnostic GEP test for use in patients with difficult-to-diagnose melanocytic lesions.
Health Care · Medical Specialities · 1,002 employees
About Exagen
XGN stock →Exagen Inc. designs, develops, and commercializes various testing products under the AVISE brand in the United States.
Health Care · Medical Specialities · 216 employees
CSTL vs XGN FAQ
Which is bigger, Castle Biosciences or Exagen?
Castle Biosciences (CSTL) is larger, with a market capitalization of $1.03B compared with $197.92M for Exagen (XGN).
Which stock has performed better over the past year, CSTL or XGN?
CSTL returned +43.98% over the past 12 months, compared with -24.27% for XGN (price return, excluding dividends). Past performance does not predict future results.
Are Castle Biosciences and Exagen in the same industry?
Yes. Both are classified in the Medical Specialities industry within the Health Care sector.