Severin Hacker - 01 Dec 2025 Form 4 Insider Report for Duolingo, Inc. (DUOL)

Reporting relationship: Chief Tech Officer, Co-Founder, Director, 10%+ Owner
Issuer ticker: DUOL
Reported as of: 01 Dec 2025
Net transaction value: -$5,691,750
SEC form: 4
Accepted by SEC: 03 Dec 2025, 19:34:44 UTC
Prior SEC filing: 20 Nov 2025
Next SEC filing: 09 Dec 2025
Source filing: View source filing
Reporting owner signature: /s/ Stephen Chen, as Attorney-in-Fact for Severin Hacker

Key filing fact

Severin Hacker filed Form 4 for Duolingo, Inc. (DUOL) on 03 Dec 2025.

Key facts

This page summarizes Severin Hacker's Form 4 filing for Duolingo, Inc. (DUOL).
5 reported transactions and 6 derivative rows are listed below.
Accepted by SEC: 03 Dec 2025, 19:34.

Change

Previous filing in this sequence was filed on 20 Nov 2025.
Current net transaction value: -$5,691,750.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001870272 Primary reporting owner

Hacker Severin

Relationship: Chief Tech Officer, Co-Founder, Director, 10%+ Owner
Address: C/O DUOLINGO, INC., 5900 PENN AVENUE, PITTSBURGH
Signature: /s/ Stephen Chen, as Attorney-in-Fact for Severin Hacker
Signature date: 03 Dec 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

DUOL holding

Class A Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 72
Date: 01 Dec 2025
Ownership: Direct

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

DUOL transaction Derivative

Performance-Based Restricted Stock Units

Options Exercise

Transaction value: $0
Shares: -60,000
Change %: -15%
Price: $0.000000
Shares after: 330,000
Date: 01 Dec 2025
Ownership: Direct
Underlying class: Class B Common Stock
Underlying amount: 60,000
Exercise price
Footnotes: F1, F2

DUOL transaction Derivative

Class B Common Stock

Options Exercise

Transaction value: $0
Shares: +60,000
Change %: +52%
Price: $0.000000
Shares after: 174,305
Date: 01 Dec 2025
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 60,000
Exercise price
Footnotes: F3

DUOL transaction Derivative

Class B Common Stock

Tax liability

Transaction value: $5,891,746
Shares: -31,770
Change %: -18%
Price: $185.45
Shares after: 142,535
Date: 01 Dec 2025
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 31,770
Exercise price
Footnotes: F3

DUOL transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value: $0
Shares: -5,252
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 03 Dec 2025
Ownership: Direct
Underlying class: Class B Common Stock
Underlying amount: 5,252
Exercise price: $38.08
Footnotes: F4

DUOL transaction Derivative

Class B Common Stock

Options Exercise

Transaction value: $199,996
Shares: +5,252
Change %: +3.7%
Price: $38.08
Shares after: 147,787
Date: 03 Dec 2025
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 5,252
Exercise price
Footnotes: F3

DUOL holding Derivative

Class B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 2,886,917
Date: 01 Dec 2025
Ownership: See footnote
Underlying class: Class A Common Stock
Underlying amount: 2,886,917
Exercise price
Footnotes: F3, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 5 footnotes

Footnote F1

Each Performance-Based Restricted Stock Unit ("PSU") represents a contingent right to receive one share of the Issuer's Class B Common Stock upon vesting. The PSUs vest upon the satisfaction of both a service-based condition and a performance-based condition. The service-based condition is satisfied as to 25% of the PSUs on each anniversary of the completion of the Issuer's initial public offering of Class A common stock based on the Reporting Person's continuous service as CTO to the Issuer through the applicable vesting dates, subject to acceleration upon a cessation of service as CTO as a result of death or permanent disability.

Footnote F2

The performance-based condition will be satisfied upon the Issuer's Class A common stock achieving certain stock price hurdles over a period of ten years. Vested PSUs will be settled by the issuance of the underlying Class B Common Stock on the first anniversary of vesting, subject to acceleration upon a termination of employment or a change in control of the Issuer.

Footnote F3

Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock in connection with: (i) any transfer, whether or not for value, except for certain permitted transfers further described in the Issuer's amended and restated certificate of incorporation, (ii) such time as the aggregate number of shares of Class B Common Stock outstanding ceases to represent 5% of the aggregate number of shares of Common Stock outstanding, and (iii) the death of the Reporting Person.

Footnote F4

The shares subject to the option are fully vested and exercisable.

Footnote F5

Shares held by SBH Trust dated March 10, 2020, of which Reporting Person is Trustee.