Hacker Severin - 20 Oct 2025 Form 4 Insider Report for Duolingo, Inc. (DUOL)

Signature
/s/ Stephen Chen, as Attorney-in-Fact for Severin Hacker
Issuer symbol
DUOL
Transactions as of
20 Oct 2025
Net transactions value
-$12,701,830
Form type
4
Filing time
22 Oct 2025, 20:16:42 UTC
Previous filing
07 Oct 2025
Next filing
06 Nov 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Hacker Severin Chief Tech Officer, Co-Founder, Director, 10%+ Owner C/O DUOLINGO, INC., 5900 PENN AVENUE, PITTSBURGH /s/ Stephen Chen, as Attorney-in-Fact for Severin Hacker 22 Oct 2025 0001870272

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction DUOL Class A Common Stock Conversion of derivative security $380,800 +10,000 +13889% $38.08 10,072 20 Oct 2025 Direct
transaction DUOL Class A Common Stock Sale $30,586 -100 -0.99% $305.86 9,972 20 Oct 2025 Direct F1
transaction DUOL Class A Common Stock Sale $184,532 -600 -6% $307.55 9,372 20 Oct 2025 Direct F1, F2
transaction DUOL Class A Common Stock Sale $154,532 -500 -5.3% $309.06 8,872 20 Oct 2025 Direct F1, F3
transaction DUOL Class A Common Stock Sale $195,882 -632 -7.1% $309.94 8,240 20 Oct 2025 Direct F1, F4
transaction DUOL Class A Common Stock Sale $311,428 -1,000 -12% $311.43 7,240 20 Oct 2025 Direct F1, F5
transaction DUOL Class A Common Stock Sale $400,152 -1,281 -18% $312.37 5,959 20 Oct 2025 Direct F1, F6
transaction DUOL Class A Common Stock Sale $156,967 -500 -8.4% $313.93 5,459 20 Oct 2025 Direct F1, F7
transaction DUOL Class A Common Stock Sale $347,365 -1,100 -20% $315.79 4,359 20 Oct 2025 Direct F1, F8
transaction DUOL Class A Common Stock Sale $506,617 -1,600 -37% $316.64 2,759 20 Oct 2025 Direct F1, F9
transaction DUOL Class A Common Stock Sale $216,025 -680 -25% $317.68 2,079 20 Oct 2025 Direct F1, F10
transaction DUOL Class A Common Stock Sale $289,085 -907 -44% $318.73 1,172 20 Oct 2025 Direct F1, F11
transaction DUOL Class A Common Stock Sale $95,991 -300 -26% $319.97 872 20 Oct 2025 Direct F1, F12
transaction DUOL Class A Common Stock Sale $128,699 -400 -46% $321.75 472 20 Oct 2025 Direct F1, F13
transaction DUOL Class A Common Stock Sale $96,927 -300 -64% $323.09 172 20 Oct 2025 Direct F1, F14
transaction DUOL Class A Common Stock Sale $32,410 -100 -58% $324.10 72 20 Oct 2025 Direct F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction DUOL Stock Option (Right to Buy) Options Exercise $0 -10,000 -28% $0.000000 25,252 20 Oct 2025 Class B Common Stock 10,000 $38.08 Direct F15
transaction DUOL Class B Common Stock Conversion of derivative security $0 +10,000 +12% $0.000000 96,075 20 Oct 2025 Class A Common Stock 10,000 Direct F16
transaction DUOL Class B Common Stock Conversion of derivative security $0 -10,000 -10% $0.000000 86,075 20 Oct 2025 Class A Common Stock 10,000 Direct F16
transaction DUOL Performance-Based Restricted Stock Units Options Exercise $0 -60,000 -13% $0.000000 390,000 20 Oct 2025 Class B Common Stock 60,000 Direct F17, F18
transaction DUOL Class B Common Stock Options Exercise $0 +60,000 +70% $0.000000 146,075 20 Oct 2025 Class A Common Stock 60,000 Direct F16
transaction DUOL Class B Common Stock Tax liability $9,935,432 -31,770 -22% $312.73 114,305 20 Oct 2025 Class A Common Stock 31,770 Direct F16
holding DUOL Class B Common Stock 2,886,917 20 Oct 2025 Class A Common Stock 2,886,917 See footnote F16, F19
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

Transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c).

Explanation of Responses:

Id Content
F1 The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on September 11, 2024.
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 $307.18 to $307.89, 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.
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 $308.61 to $309.24, 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.
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 $309.71 to $310.18, 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.
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 $310.86 to $311.81, 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.
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 $311.94 to $312.65, 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.
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 $313.65 to $314.30, 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.
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 $315.18 to $316.17, 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.
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 $316.22 to $317.19, 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.
F10 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 $317.22 to $318.20, 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.
F11 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 $318.38 to $319.26, 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.
F12 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 $319.85 to $320.21, 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.
F13 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 $321.32 to $322.19, 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.
F14 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 $322.98 to $323.25, 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.
F15 The shares subject to the option are fully vested and exercisable.
F16 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.
F17 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.
F18 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.
F19 Shares held by SBH Trust dated March 10, 2020, of which Reporting Person is Trustee.