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CSTL · Castle Biosciences Inc
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CSTL Castle Biosciences (CSTL) Insider Trading, Ownership & Congress Trades

Healthcare Services · Services-medical laboratories · CIK 0001447362
Quote by TradingView
Form 144 · 11
Insider buyers, 180 days
0
House members buying, 1 year
0
STOCK Act, US House only, disclosed up to 45 days after the trade
Funds added, last quarter
104
13F, latest reported quarter
Conversions, 180 days
28
Codes C/M, not in net · $317.9K priced

What the filings say about CSTL

Insiders, 180 days
-$9.9M net sold
4 sellers · 31% of sales under a 10b5-1 plan
Planned sales (Form 144), 90 days
$8.7M
11 notices

Castle Biosciences insider trades (Form 4)

Form 4 buys and sells (codes P and S). Grants, option exercises and conversions excluded.

Over the last 180 days, CASTLE BIOSCIENCES INC insiders sold a net $9.9M of stock across 1,159 Form 4 purchases and sales, with no insider buying. Source: SEC Form 4 filings, as of 2026-10-27.

Insider
Filed
Shares
Value
Since filing
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
SELL
2026-10-21 SECtraded 2026-10-19
8,580
$273.8K
-0.3%
Context
  • 823 earlier Form 4 trades (code P or S) here by this insider (823 sales), the last on Oct 5, 2026.
  • The trade is 68.7% of the 12,484 shares held after it.
  • 2 other insiders sold within 30 days.
  • 104 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Pres. & Chief Exec. Officer MAETZOLD DEREK J sold about $273.8K of CSTL under a 10b5-1 plan on Oct 19, 2026; 2 other insiders sold within 30 days and 104 funds added in the latest 13F quarter.
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
SELL
2026-10-21 SECtraded 2026-10-19
3,198
$102.0K
-0.3%
Context
  • 823 earlier Form 4 trades (code P or S) here by this insider (823 sales), the last on Oct 5, 2026.
  • The trade is 66.1% of the 4,840 shares held after it.
  • 2 other insiders sold within 30 days.
  • 104 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Pres. & Chief Exec. Officer MAETZOLD DEREK J sold about $102.0K of CSTL under a 10b5-1 plan on Oct 19, 2026; 2 other insiders sold within 30 days and 104 funds added in the latest 13F quarter.
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
SELL
2026-10-21 SECtraded 2026-10-19
2,718
$86.7K
-0.3%
Context
  • 823 earlier Form 4 trades (code P or S) here by this insider (823 sales), the last on Oct 5, 2026.
  • The trade is 66.1% of the 4,114 shares held after it.
  • 2 other insiders sold within 30 days.
  • 104 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Pres. & Chief Exec. Officer MAETZOLD DEREK J sold about $86.7K of CSTL under a 10b5-1 plan on Oct 19, 2026; 2 other insiders sold within 30 days and 104 funds added in the latest 13F quarter.
Juvenal Tobin W
Chief Commercial Officer
SELL
2026-10-14 SECtraded 2026-10-12
3,288
$110.6K
-2.1%
Context
  • 20 earlier Form 4 trades (code P or S) here by this insider (20 sales), the last on Sep 30, 2026.
  • The trade is 6.7% of the 48,719 shares held after it.
  • 2 other insiders sold within 30 days.
  • 104 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Chief Commercial Officer Juvenal Tobin W sold about $110.6K of CSTL under a 10b5-1 plan on Oct 12, 2026; 2 other insiders sold within 30 days and 104 funds added in the latest 13F quarter.
MAETZOLD DEREK J
Pres. & Chief Exec. Officer
SELL
2026-10-07 SECtraded 2026-10-05
8,580
$305.2K
-1.9%
Context
  • 820 earlier Form 4 trades (code P or S) here by this insider (820 sales), the last on Sep 21, 2026.
  • The trade is 40.7% of the 21,064 shares held after it.
  • 2 other insiders sold within 30 days.
  • 104 funds added in the 13F quarter to Jun 30, 2026.
Insider activity: Pres. & Chief Exec. Officer MAETZOLD DEREK J sold about $305.2K of CSTL under a 10b5-1 plan on Oct 5, 2026; 2 other insiders sold within 30 days and 104 funds added in the latest 13F quarter.
1,159 transactions on record
Since filing: total return from the first close after the filing to the latest close, dividend-adjusted. Not a forecast.
Context lines are counts over the filings above and returns from our own price history, never a price level. Not investment advice.
See all insider buying · insider selling
Showing the latest few. to see 1,154 more transactions and use the screener and CSV export. We store only your email; there is no password.
Seven facts, ranked against the sector · Rank is not a forecast
Insiders
net -$9.9M over 180 days
-$8.5M over 90 days
below 67% of Healthcare Services
Congress
no House purchase disclosed in the last 12 months
Funds
104 funds bought in last quarter
below 58% of Healthcare Services
Revenue
+3.7% year over year
below 71% of Healthcare Services
Margin
-7.0% net margin
below 63% of Healthcare Services
Buybacks
no share repurchases reported
Short interest
7.4% of the float short (float per yahoo 2026-10-26) · 4.8 days to cover · settled 2026-09-30
more than 73% of Healthcare Services
What changed in the last 30 days
Oct 21Pres. & Chief Exec. Officer MAETZOLD DEREK J sold $978.1K under a 10b5-1 plan (6 trades, Oct 5 to Oct 19)
Why it matters
A 10b5-1 plan schedules trades months ahead, so this says little about what the insider thinks today.
Oct 14Chief Commercial Officer Juvenal Tobin W sold $342.7K under a 10b5-1 plan (3 trades, Sep 29 to Oct 12)
Why it matters
A 10b5-1 plan schedules trades months ahead, so this says little about what the insider thinks today.
Oct 13Chief Commercial Officer Tobin Juvenal filed to sell $430.9K by Oct 12 (Form 144)
Why it matters
A Form 144 is a notice of intent to sell; the sale may not happen, and it says nothing about the price.
Oct 5Officer Derek Maetzold filed to sell $1.1M by Oct 5 (Form 144)
Why it matters
A Form 144 is a notice of intent to sell; the sale may not happen, and it says nothing about the price.
Oct 5Chief Operating Officer Oelschlager Kristen M sold $149.3K under a 10b5-1 plan (Oct 1)
Why it matters
A 10b5-1 plan schedules trades months ahead, so this says little about what the insider thinks today.

Watch CSTL

A free account keeps a watchlist and can send one email a day when insiders, funds or Congress file on the names in it. No password and no card.

The year, with the filings on it
Total return over 12 months. Each marker is a filing; hover or tap one for the detail.
+39.3%12M
-24%+11%+46%+81%2025-102025-122026-022026-042026-062026-082026-10 2026-08-14 · Stokes Frank sold $741.5K2025-12-15 · MAETZOLD DEREK J sold $717.4K2025-11-11 · Oelschlager Kristen M sold $664.5K2026-03-12 · MAETZOLD DEREK J sold $586.0K2025-12-17 · Oelschlager Kristen M sold $585.2K2026-03-12 · Juvenal Tobin W sold $526.6K2025-12-11 · Juvenal Tobin W sold $494.7K2025-12-16 · MAETZOLD DEREK J sold $494.2K2026-03-17 · MAETZOLD DEREK J sold $483.6K2026-03-16 · MAETZOLD DEREK J sold $453.0K2026-03-11 · MAETZOLD DEREK J sold $452.0K2026-08-24 · Oelschlager Kristen M sold $411.6K2026-08-28 · MAETZOLD DEREK J sold $380.2K2026-08-04 · MAETZOLD DEREK J sold $374.0K2026-03-13 · MAETZOLD DEREK J sold $336.0K2026-08-03 · MAETZOLD DEREK J sold $323.7K2025-10-31 · Oelschlager Kristen M sold $317.5K2026-08-25 · Juvenal Tobin W sold $317.1K2026-10-05 · MAETZOLD DEREK J sold $305.2K2026-09-21 · MAETZOLD DEREK J sold $303.2K2026-10-19 · MAETZOLD DEREK J sold $273.8K2026-09-11 · MAETZOLD DEREK J sold $267.6K2026-08-04 · MAETZOLD DEREK J sold $259.3K2026-08-25 · Oelschlager Kristen M sold $245.4K2026-07-31 · Juvenal Tobin W sold $235.0K2026-07-31 · Juvenal Tobin W sold $215.0K2025-11-25 · MAETZOLD DEREK J sold $204.9K2026-07-01 · Oelschlager Kristen M sold $199.7K2026-09-29 · Juvenal Tobin W sold $196.8K2025-11-04 · MAETZOLD DEREK J sold $196.4K2026-07-31 · MAETZOLD DEREK J sold $195.4K2025-11-11 · Stokes Frank sold $189.0K2026-08-25 · Oelschlager Kristen M sold $180.9K2026-06-16 · Oelschlager Kristen M sold $177.8K2025-11-26 · MAETZOLD DEREK J sold $170.7K2025-12-11 · Stokes Frank sold $168.4K2026-03-05 · Stokes Frank sold $167.9K2025-11-20 · Juvenal Tobin W sold $167.0K2026-01-20 · MAETZOLD DEREK J sold $160.7K2026-04-06 · MAETZOLD DEREK J sold $155.5K2026-07-01 · MAETZOLD DEREK J sold $150.9K2026-08-04 · MAETZOLD DEREK J sold $149.8K2026-10-13 · Tobin Juvenal filed to sell $430.9K2026-10-05 · Derek Maetzold filed to sell $1.1M2026-10-01 · KRISTEN OELSCHLAGER filed to sell $147.6K2026-09-14 · Tobin Juvenal filed to sell $440.6K2026-09-11 · Derek Maetzold filed to sell $938.0K2026-08-25 · Tobin Juvenal filed to sell $787.5K2026-08-24 · Kristen M. Oelschlager filed to sell $841.4K2026-08-14 · FRANKLIN M. STOKES filed to sell $741.5K2026-08-14 · Derek Maetzold filed to sell $764.0K2026-07-31 · Derek Maetzold filed to sell $1.9M2026-07-31 · Tobin Juvenal filed to sell $630.0K2026-07-01 · Derek Maetzold filed to sell $589.2K
Insider sellForm 144 (planned sale)
Indexed to 100, dividend-adjusted, not a price chart. When a name files heavily, the largest trades are drawn first.

Who owns CSTL: institutional holders (13F)

13F holdings, latest reported quarter
BlackRock, Inc.
3,291,963 sh
$78.5M
RTW INVESTMENTS, LP
2,778,335 sh
$66.3M
PRINCIPAL FINANCIAL GROUP INC
1,726,648 sh
$41.2M
VANGUARD CAPITAL MANAGEMENT LLC
1,226,497 sh
$29.3M
Allianz Asset Management GmbH
879,258 sh
$21.0M

Congress trades in CSTL

No Congress trades reported
No House member has disclosed a trade in this stock. See what Congress is buying.

Activist and 5% holders (13D/13G)

No 5%+ ownership filings
Nobody has filed for crossing 5%. That is a fact, not missing data.

CSTL planned insider sales (Form 144)

Notice of intent to sell, filed before any sale
Tobin Juvenal
Filed 2026-10-13
$430.9K
Derek Maetzold
Filed 2026-10-05
$1.1M
KRISTEN OELSCHLAGER
Filed 2026-10-01
$147.6K
Tobin Juvenal
Filed 2026-09-14
$440.6K
Derek Maetzold
Filed 2026-09-11
$938.0K

CSTL mutual fund holders (N-PORT)

Funds ranked by the share of their own portfolio in this stock (N-PORT).
Advisors Capital Small/Mid Cap Fund
$3.2M position · as of 2026-06-30
2.5%
Buffalo Small Cap Growth Fund
$5.7M position · as of 2026-06-30
1.2%
Allspring Emerging Growth Fund
$3.8M position · as of 2026-07-31
1.2%
State Street(R) SPDR(R) S&P(R) Health Care Services ETF
$1.6M position · as of 2026-06-30
1.2%
Wasatch Micro Cap Fund
$6.6M position · as of 2026-06-30
1.0%
SmallCap Fund
$20.3M position · as of 2026-07-31
1.0%
SEC N-PORT, monthly, about 60 days late · funds ≥ $10M · % is the share of the fund's own portfolio
Executive pay vs shareholder return · Mr. Maetzold
CEO pay, headline and as actually paid, against the company's return and its chosen peers' (DEF 14A).
FY
CEO total
Actually paid
Other execs, avg
TSR
Peer TSR
2025
$6.8M
$13.2M
$2.4M
-42%
+25%
2024
$6.9M
$10.0M
$2.4M
-60%
-7%
2023
$1.6M
$779.8K
$845.9K
-68%
-6%
2022
$7.6M
$3.1M
$2.7M
-65%
-10%
2021
$6.5M
$2.1M
$2.8M
-36%
+0%
Tagged by the company under SEC Item 402(v). Returns are cumulative from the start of the disclosure period. Green where the company beat its own peer group.
Live price
Daily candles from TradingView, under their licence. No filings marked.
Why this name is on the desk
Insiders have filed to sell, before selling.
The record shows a net $9.9M sold by insiders over 180 days, 104 funds added last quarter, $8.7M in planned Form 144 sales. Each figure is a federal filing, dated the day it went public.
Backtest this pattern Open the screener
Same sector, ranked by filing activity
Sector by SEC SIC code
NTRAPGNYHIMSWGSPRVATDOCAVAHGHADUSSERABDSXBLLN

CSTL financials

Revenue growth
+3.7%
XBRL, annual
Net margin
-7.0%
Ratios from the company's XBRL filings, latest filings
Revenue, TTM
$357.3M
four quarters, 2025-07-01 to 2026-06-30
Net margin, TTM
-5.4%
net income over revenue, 2025-07-01 to 2026-06-30
Free cash flow, TTM
-$489.0K
operating cash flow minus capex, 2025-07-01 to 2026-06-30
Debt to equity
0.02x
long-term 2026-06-30 plus current 2026-06-30; equity 2026-06-30
Cash flow to debt
4.23x
TTM operating cash flow over long-term 2026-06-30 plus current 2026-06-30
Return on equity
-4.2%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on assets
-3.5%
TTM net income over average of 2025-06-30 and 2026-06-30
Return on invested capital
n/a
tax provision or pre-tax income not filed for the four quarters
Return on capital employed
-6.4%
operating income (EBIT proxy) over average of 2025-06-30 and 2026-06-30 minus current liabilities
P/E, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Enterprise value
$958.5M
market value at close 2026-10-23 on 2026-07-23 shares, plus long-term 2026-06-30 plus current 2026-06-30, minus cash 2026-06-30
FCF yield
-0.0%
TTM free cash flow over market value at close 2026-10-23
PEG, trailing
n/a
trailing loss, a multiple of a loss is not meaningful
Price as of 2026-10-23. Hover or tap a tile for its yearly and quarterly history.
Method
TTM is four consecutive fiscal quarters; Q4 is the year minus nine months when not filed. Returns use the average of opening and closing balances. EBIT is approximated by operating income. PEG uses trailing EPS growth.
Fundamentals
Annual figures from XBRL filings. Pick a past date to see them as known then.
2025-122024-122023-122022-12
Revenue$344.2M$332.1M$219.8M$137.0M
Operating income-$42.8M$8.7M-$68.0M-$72.9M
Net income-$24.2M$18.2M-$57.5M-$67.1M
EPS (diluted)-0.830.62-2.14-2.58
Operating cash flow$64.3M$64.9M-$5.6M-$41.7M
Cash$116.7M$119.7M$98.8M$122.9M
Long-term debt$9.6M$9.7M$0n/a
SEC XBRL, fiscal years, as known on 2026-10-27

CSTL Stock Sonar score 6/7 axes

Find similar shapesCompare

CSTL ranks highest on financial health (87th percentile) and profitability (44th), and lowest on insider conviction (17th), among Healthcare Services peers.

ProfitHealthGrowthInsidersInstitutionsRisk
Profitability
44
Inputs
  • Return on equity-4.2% · 46 pct, sector of 70
  • Return on assets-3.5% · 46 pct, sector of 88
  • Return on invested capitaltax provision or pre-tax income not filed for the four quarters
  • Return on capital employed-6.4% · 39 pct, sector of 68
Financial health
87
Inputs
  • Debt to equity0.02x · 82 pct, sector of 61
  • Cash flow to debt4.23x · 92 pct, sector of 66
Growth
29
Inputs
  • Revenue growth, YoY+3.7% · 29 pct, sector of 87
  • Backlog growth, YoYno backlog line filed, or no year-earlier backlog
Insider conviction
17
Inputs
  • Net Form 4 buying (codes P and S), 180d-$6.1M · 35 pct, sector of 64
  • Insider buyers, 180d0 · 0 pct, sector of 64
Institutional and government
33
Inputs
  • Funds adding, latest quarter104 · 42 pct, sector of 73
  • Congress net buyers, 365dno Congress trades in 365 days
  • Federal contracts, 180dno federal contracts in 180 days
  • Lobbying spend, 4 quarters$160K · 25 pct, universe of 1,063
Risk and compliance
37
Inputs
  • Short interest, % of float+7.4% · 37 pct, sector of 95
  • Recalls per $1B revenue, 3ynot measured for this sector, almost no peer has an event
  • EPA cases per $1B revenue, 5ynot measured for this sector, almost no peer has an event
  • New text in Risk Factors, latest 10-K+13.2% · 37 pct, sector of 72
1 not measured: US patents
  • US patents needs 1 of 2 inputs, 0 present: patent data not loaded yet

6 of 7 axes scored. Each is a percentile against sector peers (all companies when the sector is thin); higher is better. An unscored axis is unmeasured, not low. How it is scored

CSTL filings, in plain words

Are Castle Biosciences insiders buying or selling CSTL?

In the 180 days to 2026-10-27, Castle Biosciences insiders were net sellers, a net $9.9M across purchases and sales reported on Form 4, by 4 sellers.

Are there planned insider sales of CSTL?

Yes. 11 Form 144 notices of planned insider sales were filed in the 90 days to 2026-10-27, covering $8.7M of stock; the latest, by Tobin Juvenal, was filed 2026-10-13.

Read the full summary

In the 180 days to 2026-10-27, Castle Biosciences insiders were net sellers of CSTL, a net $9.9M across purchases and sales reported on Form 4 by 4 sellers. 31% of the 108 insider sales were made under a Rule 10b5-1 plan; the rest were not flagged as planned. Insiders filed 11 Form 144 notices of intent to sell in the 90 days to 2026-10-27, covering $8.7M of stock. Each figure is counted from SEC and House filings as of 2026-10-27, dated the day the filing was made public.

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