Insider buying last 90 days
No open-market insider purchases were filed for CSTL in the last 90 days.
From Form 4 filings, dated to when each was filed.
Every CSTL insider filing, plotted on the chart in Gekko.Open CSTL in Gekko
NASDAQ: CSTL
Castle Biosciences (CSTL) Stock Analysis & Forecast
Oct 12 close
$32.76−1.66 (−4.8%)
Gekko Brief
AI summaryOct 12 closeThis week's news centers on new clinical data for Castle Biosciences' DecisionDx-Melanoma test presented at the EADV Congress 2026, alongside an AdvanceAD-Tx study in atopic dermatitis, which drew positive investor attention. Alongside this, several insider sales were reported, including CEO Derek Maetzold selling over 14,000 shares worth approximately $515,000 on October 5 under a pre-arranged trading plan, and COO Kristen Oelschlager's sale of 4,153 shares, which coincided with a stock drop of 8.98% to $33.36 on October 6. Separately, analysts maintain a "Moderate Buy" consensus, with a target price cited at $42.00 in one report.
CSTL closed at $32.76, down 4.8%, with its close sitting between the 50-day average of $33.36 and the 200-day average of $28.91. The GekkoIndex reads 60.3, placing the stock in the Accumulation zone. The price sits 13.9% below Gekko Fair Value, which stands at $38.04.
Over the next 20 trading days, the company reports earnings on 2 November, falling inside this window and following a prior quarter where actual EPS of -$0.49 beat the -$0.47 estimate, though the last reaction was -6.1%. Seasonality from this point in the calendar has averaged a 12.4% gain over 5 years, rising in 4 of them. No insider, Congress, or unusual options activity appears within their respective windows.
Written by AI from the Oct 12, 2026 close and checked automatically against the figures on this page.
Castle Biosciences price vs fair value
Close $32.76200-day averageGekko Fair Value $38.04
Castle Biosciences quick facts
- Market cap
- $1.00B
- P/E ratio
- —
- Forward P/E
- —
- EPS, TTM
- −$0.64
- Revenue, TTM
- $357.3M
- Profit margin
- -5.4%
- Dividend yield
- —
- Beta
- 0.95
- Volume
- 238,969 avg 404,813
- 1-year return
- +38.5%
- Typical daily move
- ±5.4%
- Typical 20-day move
- ±12.6%
- 50-day average
- $33.36
- 200-day average
- $28.91
- Next earnings
- Nov 2 after close
- Shares outstanding
- 30.55M
Castle Biosciences swing-trade checklist
Castle Biosciences scores 3 supportive, 1 mixed and 1 headwind across the 5 checklist items with data.
Six things swing traders check before a 20-day hold, read from the latest data.
3 supportive1 mixed1 headwind
- Trendmixed
Averages disagree
Close $32.76 sits between the 50-day ($33.36) and 200-day ($28.91) averages, or the averages disagree.
See the chart - GekkoIndexsupportive
60.3, Accumulation
Reading 60.3 is in the Accumulation zone.
See the GekkoIndex - Fair valuesupportive
13.9% below
Price is 13.9% below Gekko Fair Value (more than 5% below).
See fair value - Smart moneyno data
No data
No insider, Congress or unusual options activity in the window.
See smart money - Earnings riskheadwind
Reports in 21 days
Reports on Nov 2, 2026, 21 days away — inside a typical 20-trading-day hold.
See earnings - Seasonalitysupportive
+12.4% on average
From this point in the calendar, the next 20 trading days averaged +12.4% over 5 years, rising in 4 of them.
See seasonality
A description of current data, not a recommendation. How this page works
Castle Biosciences stock chart and price history
Castle Biosciences closed at $32.76 on Oct 12, 2026, +38.5% over the past year, inside a 52-week range of $17.72 to $44.28.
Close50-day average200-day averageVolume
Use the left and right arrow keys to read daily values.
Performance Breakdown
- 1 month
- +1.3%
- 3 months
- +41.7%
- 6 months
- +39.2%
- 1 year
- +38.5%
The full CSTL chart adds GekkoIndex, insider, options, Congress and hedge fund markers, plus TrendCandles™.Open CSTL in Gekko
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About Castle Biosciences
Castle Biosciences provides diagnostic and prognostic testing aimed at skin cancers. Its best-known offering, DecisionDx-Melanoma, is a multi-gene expression profile assay that helps estimate the chance of metastasis in patients with invasive cutaneous melanoma.
Beyond that core test, the company has built a set of proprietary gene expression profile tools for related conditions. DecisionDx-UM addresses metastasis risk in uveal melanoma, a cancer of the eye, while DecisionDx-SCC uses a 40-gene profile to gauge metastasis risk in squamous cell carcinoma for patients with known risk factors. It also offers DecisionDx DiffDx-Melanoma and myPath Melanoma, which support diagnosis of pigmented lesions that are otherwise hard to classify. Patients access these tests through their healthcare providers rather than directly from the company.
Castle Biosciences began operating in 2007 and is headquartered in Friendswood, Texas. Its shares trade on the NASDAQ under the ticker CSTL.
- Listed
- NASDAQ
- Sector
- Health technology
- Industry
- Medical specialties
- Website
- castlebiosciences.com
Castle Biosciences GekkoIndex: the smart money zone
Castle Biosciences’s GekkoIndex — Gekko’s 0 to 100 smart money score — reads 60.3, in the Accumulation zone, up 9.5 points over five sessions.
60.3Accumulation
Up 9.5 points over five sessions, from the Neutral zone.
Reading for Oct 12, 2026
What followed past readings in each zone
| Zone | Readings | 5 days | 20 days | ||
|---|---|---|---|---|---|
| Buying | 57 | +0.7% | +2.7% | ||
| Accumulation (current zone) | 202 | −0.1% | +1.0% | ||
| Neutral | 360 | +1.2% | +4.7% | ||
| Distribution | 55 | +0.9% | −1.3% | ||
| Selling | 8 | Too few readings yet | |||
Average CSTL share-price change over the trading days after each daily reading in its GekkoIndex history. Across every stock Gekko tracks, Accumulation readings averaged +2.2% over 20 days. Past behaviour doesn’t guarantee future results.
Accumulation zone: Institutional interest building. About the five zones →
See every daily GekkoIndex reading plotted over the CSTL price, zone by zone.Track CSTL in Gekko
Is Castle Biosciences stock overvalued? Gekko Fair Value
Castle Biosciences trades 13.9% below Gekko Fair Value of $38.04, so the shares are undervalued on Gekko’s estimate.
Gekko’s own estimate of what Castle Biosciences shares are worth, recalculated every trading day.
$38.04
Gekko Fair Value, Oct 10, 2026
13.9% Undervalued
At the end of Aug 2026 the price was 13.5% below the estimate.
Gekko Fair ValueShare price, month end
Gekko Fair Value on every chart, with the gap to price updating daily.Open CSTL in Gekko
Castle Biosciences insider and Congress trading
No open-market insider purchases were filed for Castle Biosciences, and no Congress trades were disclosed, in the last 90 days.
Plus buybacks, unusual options and fund positions, each dated to when it became public.
Congress trades last 90 days
No trades in CSTL were disclosed by members of Congress in the last 90 days.
From congressional disclosures, which report amounts as ranges.
Congress disclosures for CSTL, plotted on the chart in Gekko.Open CSTL in Gekko
Castle Biosciences earnings: next date and track record
Castle Biosciences reports on Nov 2, 2026, after the close (21 days away), and beat the EPS estimate in 6 of its last 8 reports.
Next earnings report
Nov 2, 2026
Expected after the close, 21 days away
- EPS estimate
- −$0.35
- Revenue estimate
- $92.26M
6 of 8reports beat the EPS estimate
±11.8%average move across the report
4 of 8reports followed by a gain
Share-price move across each report
| Reported | EPS | Revenue | Move |
|---|---|---|---|
| May 11, 2026 | −$0.49 est −$0.47 | — | −6.1% |
| Feb 26, 2026 | −$0.08 est −$0.23 | $87.01M est $79.89M | −4.1% |
| Nov 3, 2025 | −$0.02 est −$0.34 | $83.04M est $80.38M | +24.0% |
| Aug 4, 2025 | $0.15 est −$0.51 | $86.19M est $68.00M | +38.9% |
| Apr 30, 2025 | −$0.90 est −$0.07 | $87.99M est $71.82M | −2.7% |
| Feb 26, 2025 | $0.32 est $0.04 | $86.31M est $83.89M | +0.8% |
| Nov 4, 2024 | $0.08 est −$0.06 | $85.78M est $80.58M | −6.0% |
| Aug 5, 2024 | $0.31 est −$0.27 | $87.00M est $69.34M | +11.8% |
“Move” is the close of the first session after the report compared with the close of the last session before it, so it reads the same whether the company reported before the open or after the close.
Castle Biosciences stock forecast and analyst price targets
Analysts’ average 12-month price target for Castle Biosciences is $45.22, +38.0% from the last close, from 5 firms rating the stock in the last 90 days.
$45.22consensus 12-month target, +38.0% from the last close
Now $32.76Avg $45.22
Low $36High $57
Each firm’s latest rating in the last 90 days: 5 firms.
Latest analyst actions
| Date | Firm | Target | vs price |
|---|---|---|---|
| Oct 1 | Lake Street | $57 | +74.0% |
| Sep 22 | Roth MKM | $50 | +52.6% |
| Aug 3 | BTIG | $44 | +34.3% |
| Aug 2 | Canaccord Genuity | $40 | +22.1% |
| Jul 31 | Roth MKM | $40 | +22.1% |
+1.0%average 20-day move after past Accumulation readings
+12.4%average move over the next 20 trading days in the last 5 years
±5.4%typical daily move, from the 14-day average range
Gekko doesn’t publish price predictions. These are analyst targets and historical base rates, which don’t guarantee future results.
Castle Biosciences seasonality: the next 20 trading days
Over the next 20 trading days from Oct 10, Castle Biosciences averaged +12.4% across the last 5 years, rising in 4 of them.
Next 20 trading days, by year
Average move and hit rate
| Window | Average | Years higher |
|---|---|---|
| Next 5 trading days | +1.1% | 2 of 5 |
| Next 10 trading days | −1.0% | 3 of 5 |
| Next 15 trading days | +10.0% | 5 of 5 |
| Next 20 trading days | +12.4% | 4 of 5 |
| Next 30 trading days | +11.1% | 2 of 5 |
For scale, CSTL’s typical 20-trading-day move in either direction is about 12.6%.
Castle Biosciences market cap and key statistics
Castle Biosciences’s market cap is $1.00B and revenue of $357.3M over the last twelve months.
Valuation
- Market cap
- $1.00B
- EPS, TTM
- −$0.64
- Gekko Fair Value
- $38.04
Trading
- Volume
- 238,969
- Avg volume, 20 days
- 404,813
- 52-week high
- $44.28
- 52-week low
- $17.72
- Shares outstanding
- 30.55M
Financials
- Revenue, TTM
- $357.3M
- Profit margin
- -5.4%
- Return on equity
- -4.2%
- Quarterly earnings growth, YoY
- −51.6%
Risk and income
- Beta
- 0.95
- Typical daily move
- ±5.4%
- Typical 20-day move
- ±12.6%
Castle Biosciences stock news this week
Coverage of Castle Biosciences this week reads neutral: 4 positive, 9 neutral and 3 negative headlines.
- Form 4 Castle Biosciences Inc For: 10 October By Investing.comInvesting.com South Africa, Oct 11
- Castle Biosciences president and CEO Derek Maetzold sells $515k stockInvesting.com, Oct 11
- Castle Biosciences, Inc. (NASDAQ:CSTL) Stock Has Consensus Target Price of $42.00 According to BrokeragesMarketBeat, Oct 9
- Castle Biosciences (CSTL) Could Be 23% Undervalued Following Fresh Melanoma DataSimply Wall Street, Oct 9
- Castle Biosciences (NASDAQ:CSTL) Insider Derek Maetzold Sells 8,580 Shares of Company StockMarketBeat, Oct 7
- Castle Biosciences CEO Derek Maetzold Executes Option Exercise and Sells 14,496 Shares on October 5, 2026Kalkine Media, Oct 7
Castle Biosciences peers
Castle Biosciences’s 6 largest industry peers by market value, with today’s move, GekkoIndex zone and gap to Gekko Fair Value.
| Stock | GekkoIndex zone | vs Fair Value |
|---|---|---|
| TMOThermo Fisher Scientific | Neutral | 18.2% above |
| ABTAbbott Laboratories | Neutral | 14.7% below |
| DHRDanaher | Neutral | 4.5% above |
| ISRGIntuitive Surgical | Neutral | 18.8% above |
| MDTMedtronic | Neutral | 22.9% below |
| SYKStryker | Accumulation | 12.6% below |
A peer links to its own page where one exists.
Castle Biosciences stock FAQ
What is Castle Biosciences’s market cap?
Castle Biosciences’s market cap is $1.00B at the Oct 12, 2026 close of $32.76, with 30.55M shares outstanding.
What is the Castle Biosciences stock forecast?
The consensus analyst 12-month price target for Castle Biosciences is $45.22, +38.0% from the last close. Of the 5 firms that rated the stock in the last 90 days, 5 rate it a buy, 0 a hold and 0 a sell. Gekko doesn’t publish price predictions of its own.
Is Castle Biosciences stock overvalued or undervalued?
On Gekko’s estimate Castle Biosciences is undervalued: the Oct 12, 2026 close of $32.76 is 13.9% below Gekko Fair Value of $38.04. Gekko Fair Value is recalculated every trading day, and a gap inside 5% either way counts as about fair value.
When does Castle Biosciences report earnings next?
Castle Biosciences is expected to report on Nov 2, 2026, after the market closes (21 days away). Analysts expect earnings of −$0.35 per share on revenue of $92.26M. Castle Biosciences beat the earnings estimate in 6 of its last 8 reports, moving 11.8% on average across the report.
What is Castle Biosciences’s 52-week high and low?
Castle Biosciences’s 52-week high is $44.28 and its 52-week low is $17.72; it closed at $32.76 on Oct 12, 2026, +38.5% over the past year. Over the last five years the shares peaked at $68.65 on Oct 19, 2021.
Is Castle Biosciences stock a buy right now?
Gekko describes the data; it does not make buy or sell recommendations. On the swing-trade checklist, 3 of the 5 items with data read as supportive (gekkoindex, fair value and seasonality), 1 as mixed (trend) and 1 as a headwind (earnings risk). The checklist is a description of current data, not a recommendation.
How this page works
During US trading hours the price at the top of the page is a delayed quote, refreshed every 15 minutes; everything else is rebuilt after each US market close. The GekkoIndex, Gekko Fair Value and the checklist are Gekko’s own, and the Gekko Brief is written by AI from this page’s data and checked against it before it is published. How Gekko’s data works →
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