CASTLE BIOSCIENCES INC

CSTL

Form 4 • Statement of Changes in Beneficial Ownership

SEC Accession Number: 0001628280-26-015352
Filing date: Mar 5, 2026
Earliest execution date: Mar 3, 2026
Reporting Owners: Oelschlager Kristen M (COO)

Summary

Type

Sell

Net shares

-9,219

% of shares

-5.57%

Amount (USD)

$258,243

Insider confidence score

40.0 out of 100

Positive

  • Tax withholding obligation

Negative

  • Large tax withholding sell (≥1% of shares)
  • Large sell amount ($250K+)

Stock transactions

Transaction 1

Security

Common Stock

Action

Tax_withhold

Date

2026-03-03

Code

F

Net shares

-2,427.0

Price per Share

$27.57

Amount (USD)

$66,912.39

Acquired/Disposed

Disposed

Shares Owned Before

22,495.0

Shares Owned After

20,068.0

Transaction 2

Security

Common Stock

Action

Exercise

Date

2026-03-04

Code

M

Net shares

+25,771.0

Acquired/Disposed

Acquired

Shares Owned Before

20,068.0

Shares Owned After

45,839.0

Transaction 3

Security

Common Stock

Action

Tax_withhold

Date

2026-03-04

Code

F

Net shares

-6,792.0

Price per Share

$28.17

Amount (USD)

$191,330.64

Acquired/Disposed

Disposed

Shares Owned Before

45,839.0

Shares Owned After

39,047.0

Derivative Transactions

Transaction 1

Security

Restricted Stock Units

Action

Grant

Date

2026-03-03

Code

A

Net shares

+48,367.0

Acquired/Disposed

Acquired

Shares Owned Before

0.0

Shares Owned After

48,367.0

Transaction 2

Security

Restricted Stock Units

Action

Exercise

Date

2026-03-04

Code

M

Net shares

-13,811.0

Acquired/Disposed

Disposed

Shares Owned Before

41,432.0

Shares Owned After

27,621.0

Transaction 3

Security

Restricted Stock Units

Action

Exercise

Date

2026-03-04

Code

M

Net shares

-11,960.0

Acquired/Disposed

Disposed

Shares Owned Before

47,838.0

Shares Owned After

35,878.0

Filing's footnotes

1. Reflects the withholding of shares of the Issuer's common stock to satisfy tax withholding obligations in connection with the delivery of vested performance stock units reported on January 12, 2026.

2. Includes 965 shares acquired on February 27, 2026, under the Issuer's employee stock purchase plan.

3. Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Common Stock.

4. Held by the Fritz Shorter Trust of which the Reporting Person and her spouse are the trustees and beneficiaries.

5. The RSU's vest in four equal annual installments beginning on March 03, 2027.

6. On March 4, 2024, the Reporting Person was granted 55,243 RSUs which vest in four equal installments beginning on March 4, 2025.

7. On March 4, 2025, the Reporting Person was granted 47,838 RSUs which vest in four equal installments beginning on March 4, 2026.

This page is for informational purposes only. While we strive for accuracy, the summary may contain inaccuracies or omissions. Please refer to the official SEC filing for authoritative information. Open the SEC filing.