Transaction · 0001628280-26-065327

MAETZOLD DEREK J

MAETZOLD DEREK J, PRES, CEO, reported an open-market or private sale at CASTLE BIOSCIENCES INC involving 3198.000000 shares for an estimated $113740.07. Reported holdings after the transaction were 8038.000000 shares. The stored filing text includes a detected 10b5-1 reference.

Open-market sellSEC transaction code SPRES, CEO
CSTLCASTLE BIOSCIENCES INC
Filing timeOct 07
Trade dateOct 05, 2026
Filing · SECView on SEC
InsiderProfile
% of reported position traded28.46%Shares sold ÷ (holdings after + shares sold). Estimated position before: 11,236 shares.

Row-level estimate for this security and ownership context, not the insider’s complete portfolio. Joint ownership, other transactions in the filing, amendments and footnotes can affect interpretation.

Price performance since filing

Close on the filing date, the pre-filing context, and the forward return at standard windows
Price at filing
$33.36
Pre-filing
1mo ago -1.4%1w ago +7.7%1d ago +6.6%
Returns since
7d30d90d180d1y

CSTL price since this filing

30 days of pre-filing context and vertical markers at the filing date plus 7d / 30d / 90d / 180d / 1y afterwards
CSTL since 2026-10-07Filed yesterday · 1 day of post-filing data
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Filing datePost-filing windows (7d, 30d, 90d, 180d, 1y)30 days of pre-filing context

Transaction facts

Stored Form 4 columns with their raw values

Non-derivative
Type
Sell
Code S
Identifier
0001628280-26-065327
Common Stock
Transaction date
Oct 05, 2026
Filed Oct 07, 2026, 08:10 PM · 2d delay
Shares
3.19k sh
$35.57 per share
Estimated value
-$113k
Computed from shares × price
Holdings after
8.03k sh
Indirect · By The Maetzold Descendants 2020 Trust

Filing signal explanations

Badges describe filing facts only — not predictions.

Cluster 14dRepeat 30dPattern $100kLarge $1.00M
Cluster Selling Large Holdings Reduction Large Sale Repeat Seller 10b5-1 Detected
-6score
Filing-only score

-6

Compact filing score computed from stored Form 4 facts. Version v1.

Mixed or weak signal

This filing has a negative filing-only score. It may be less informative as an insider-activity signal and needs extra context.

Reported relationships & other filings

Form 4 relationship flags and nearby filing context

Reported roles

Pres. & Chief Exec. Officer

Officer YesDirector Yes10% NoOther No
Footnotes & amended
  1. F1

    These transactions were made pursuant to a Rule 10b5-1 plan adopted by the Reporting Person on June 2, 2026.

  2. F2

    This transaction was executed in multiple trades at prices ranging from $35.310 to $35.965, inclusive. The price reported above reflects the weighted-average sale price. The Reporting Person hereby un…

  3. F3

    Held by The Maetzold Descendants 2020 Trust of which the Reporting Person's spouse is the trustee and the Reporting Person's spouse and their children are beneficiaries.

  4. F4

    Held by Derek Maetzold 2020 Irrevocable Trust of which the Reporting Person is the trustee and his children are beneficiaries.

  5. F5

    Held by The Maetzold 2018 Remainder Trust FBO Emily Carol Kirk of which the Reporting Person is the trustee and his child is the beneficiary.

  6. F6

    Held by The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.

  7. F7

    Held by The Maetzold 2018 Remainder Trust FBO John Derek Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.

  8. F8

    Held by The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold of which the Reporting Person is the trustee and his child is the beneficiary.

  9. F9

    Held by DJM Grantor Retained Annuity Trust No. 6 of which the Reporting Person is the trustee and the beneficiaries are The Maetzold 2018 Remainder Trust FBO John Derek Maetzold, The Maetzold 2018

  10. Remainder Trust FBO Emily Carol Kirk, The Maetzold 2018 Remainder Trust FBO Peter Douglas Maetzold and The Maetzold 2018 Remainder Trust FBO Hannah Elizabeth Maetzold.

  11. F10

    Held by DJM Grantor Retained Annuity Trust No. 7 of which the Reporting Person is the trustee and beneficiary.

  12. F11

    Held by DJM Grantor Retained Annuity Trust No. 8 of which the Reporting Person is the trustee and beneficiary.

  13. F12

    Held by DJM Grantor Retained Annuity Trust No. 9 of which the Reporting Person is the trustee and beneficiary.

  14. F13

    The shares subject to the option are fully vested.

Original filing · 0001628280-26-065327
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