Septerna, Inc.

SEPN

Form 4 • Statement of Changes in Beneficial Ownership

SEC Accession Number: 0001193125-26-092050
Filing date: Mar 4, 2026
Earliest execution date: Mar 2, 2026

Summary

Type

Sell

Net shares

-70,453

% of shares

-98.89%

Amount (USD)

$1,979,838

Insider confidence score

8.8 out of 100

Positive

  • Under Rule 10b5-1 trading plan

Negative

  • Extreme scheduled sell (≥25% of shares)
  • Very large sell amount ($1M+)

Stock transactions

Transaction 1

Security

Common Stock

Action

Exercise

Date

2026-03-02

Code

M

Net shares

+53,714.0

Price per Share

$1.55

Amount (USD)

$83,256.70

Acquired/Disposed

Acquired

Shares Owned Before

793.0

Shares Owned After

54,507.0

Transaction 2

Security

Common Stock

Action

Exercise

Date

2026-03-02

Code

M

Net shares

+11,638.0

Price per Share

$2.76

Amount (USD)

$32,120.88

Acquired/Disposed

Acquired

Shares Owned Before

54,507.0

Shares Owned After

66,145.0

Transaction 3

Security

Common Stock

Action

Exercise

Date

2026-03-02

Code

M

Net shares

+5,101.0

Price per Share

$2.76

Amount (USD)

$14,078.76

Acquired/Disposed

Acquired

Shares Owned Before

66,145.0

Shares Owned After

71,246.0

Transaction 4

Security

Common Stock

Action

Sell

Date

2026-03-02

Code

S

Net shares

-4,090.0

Price per Share

$27.51

Amount (USD)

$112,496.27

Acquired/Disposed

Disposed

Shares Owned Before

71,246.0

Shares Owned After

67,156.0

Transaction 5

Security

Common Stock

Action

Sell

Date

2026-03-02

Code

S

Net shares

-66,363.0

Price per Share

$28.14

Amount (USD)

$1,867,342.00

Acquired/Disposed

Disposed

Shares Owned Before

67,156.0

Shares Owned After

793.0

Derivative Transactions

Transaction 1

Security

Stock Option (Right to Buy)

Action

Exercise

Date

2026-03-02

Code

M

Net shares

-53,714.0

Acquired/Disposed

Disposed

Shares Owned Before

69,683.0

Shares Owned After

15,969.0

Transaction 2

Security

Stock Option (Right to Buy)

Action

Exercise

Date

2026-03-02

Code

M

Net shares

-11,638.0

Acquired/Disposed

Disposed

Shares Owned Before

15,098.0

Shares Owned After

3,460.0

Transaction 3

Security

Stock Option (Right to Buy)

Action

Exercise

Date

2026-03-02

Code

M

Net shares

-5,101.0

Acquired/Disposed

Disposed

Shares Owned Before

10,202.0

Shares Owned After

5,101.0

Filing's footnotes

1. Includes 793 shares acquired under the Septerna, Inc. 2024 Employee Stock Purchase Plan on October 31, 2025 in a transaction that was exempt under Rule 16b-3(c).

2. This transaction was effected pursuant to a Rule 10b5-1 sales plan adopted by the Reporting Person on October 31, 2025.

3. The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $26.90 to $27.89. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.

4. The price reported in Column 4 is a weighted average price. The shares were purchased in multiple transactions at prices ranging from $27.90 to $28.70. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range.

5. 25% of the shares underlying this option vested on February 1, 2024, with the remainder vesting in thirty-six substantially equal monthly installments thereafter, subject to the Reporting Person's continuous service the Issuer on each such vesting date.

6. 1/48th of the shares subject to such option vest and become exercisable in substantially equal monthly installments on each monthly anniversary of March 1, 2024, subject to the Reporting Person's continuous service to the Issuer on each such date.

ℹ️ Filed under Rule 10b5-1 trading plan

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.