Severin Hacker - 19 Nov 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: 19 Nov 2025
Net transaction value: -$1,346,641
SEC form: 4
Accepted by SEC: 20 Nov 2025, 17:38:26 UTC
Prior SEC filing: 06 Nov 2025
Next SEC filing: 03 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 20 Nov 2025.

Key facts

This page summarizes Severin Hacker's Form 4 filing for Duolingo, Inc. (DUOL).
12 reported transactions and 4 derivative rows are listed below.
Accepted by SEC: 20 Nov 2025, 17:38.

Change

Previous filing in this sequence was filed on 06 Nov 2025.
Current net transaction value: -$1,346,641.

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: 20 Nov 2025

Reported non-derivative transactions

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

DUOL transaction

Class A Common Stock

Conversion of derivative security

Transaction value: $380,800
Shares: +10,000
Change %: +13889%
Price: $38.08
Shares after: 10,072
Date: 19 Nov 2025
Ownership: Direct

DUOL transaction

Class A Common Stock

Sale

Transaction value: $194,324
Shares: -1,146
Change %: -11%
Price: $169.57
Shares after: 8,926
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F2

DUOL transaction

Class A Common Stock

Sale

Transaction value: $170,549
Shares: -1,000
Change %: -11%
Price: $170.55
Shares after: 7,926
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F3

DUOL transaction

Class A Common Stock

Sale

Transaction value: $344,534
Shares: -2,009
Change %: -25%
Price: $171.50
Shares after: 5,917
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F4

DUOL transaction

Class A Common Stock

Sale

Transaction value: $220,831
Shares: -1,281
Change %: -22%
Price: $172.39
Shares after: 4,636
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F5

DUOL transaction

Class A Common Stock

Sale

Transaction value: $132,046
Shares: -760
Change %: -16%
Price: $173.74
Shares after: 3,876
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F6

DUOL transaction

Class A Common Stock

Sale

Transaction value: $539,362
Shares: -3,089
Change %: -80%
Price: $174.61
Shares after: 787
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F7

DUOL transaction

Class A Common Stock

Sale

Transaction value: $76,324
Shares: -435
Change %: -55%
Price: $175.46
Shares after: 352
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F8

DUOL transaction

Class A Common Stock

Sale

Transaction value: $49,471
Shares: -280
Change %: -80%
Price: $176.68
Shares after: 72
Date: 19 Nov 2025
Ownership: Direct
Footnotes: F1, F9

Reported derivative securities

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

DUOL transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value: $0
Shares: -10,000
Change %: -66%
Price: $0.000000
Shares after: 5,252
Date: 19 Nov 2025
Ownership: Direct
Underlying class: Class B Common Stock
Underlying amount: 10,000
Exercise price: $38.08
Footnotes: F10

DUOL transaction Derivative

Class B Common Stock

Conversion of derivative security

Transaction value: $0
Shares: +10,000
Change %: +8.7%
Price: $0.000000
Shares after: 124,305
Date: 19 Nov 2025
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 10,000
Exercise price
Footnotes: F11

DUOL transaction Derivative

Class B Common Stock

Conversion of derivative security

Transaction value: $0
Shares: -10,000
Change %: -8%
Price: $0.000000
Shares after: 114,305
Date: 19 Nov 2025
Ownership: Direct
Underlying class: Class A Common Stock
Underlying amount: 10,000
Exercise price
Footnotes: F11

DUOL holding Derivative

Class B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 2,886,917
Date: 19 Nov 2025
Ownership: See footnote
Underlying class: Class A Common Stock
Underlying amount: 2,886,917
Exercise price
Footnotes: F11, F12

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

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 12 footnotes

Footnote F1

The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on September 11, 2024.

Footnote F2

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $168.98 to $169.90, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F3

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $169.99 to $170.98, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F4

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $171.00 to $171.97, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F5

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $172.01 to $172.90, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F6

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $173.12 to $174.11, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F7

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $174.14 to $175.13, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F8

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $175.14 to $176.11, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F9

The price reported in Column 4 is a weighted average sale price calculated by the broker executing the sales. These shares were sold in multiple transactions at prices ranging from $176.37 to $176.90, inclusive. The Reporting Person hereby undertakes to provide to the Securities and Exchange Commission staff, the Issuer, or a security holder of the Issuer, upon request, full information regarding the number of shares sold at each respective price within the range set forth in this footnote.

Footnote F10

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

Footnote F11

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 F12

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