[Form 4] Duolingo, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Duolingo insider Severin Hacker reported multiple transactions dated 10/06/2025. Mr. Hacker exercised a stock option to acquire 10,000 shares at an exercise price of $38.08 and simultaneously sold 10,000 Class A shares in multiple brokered trades under a Rule 10b5-1 plan at weighted average prices ranging from $316.79 to $329.19. After the activity his direct beneficial holdings of Class A common stock are reported as 72 shares, with additional direct and indirect holdings shown as exercised options and Class B/Class A shares, including 2,886,917 Class A shares held indirectly in a trust.

Positive

• Used a Rule 10b5-1 trading plan (adopted 9/11/2024), indicating preplanned transactions
• Exercised options at a low strike of $38.08, enabling liquidity at higher market prices

Negative

• Selling of 10,000 Class A shares on 10/06/2025 reduced direct holdings to 72 shares
• Large sales at market prices between $316.79 and $329.19 represent significant insider disposal on that date

Insights

Corporate Governance Specialist

Insider exercised options then sold the resulting shares under a prearranged plan.

The filings show a 10,000-share option exercise at an exercise price of $38.08 and brokered sales totaling 10,000 Class A shares executed under a Rule 10b5-1 trading plan adopted 9/11/2024. The use of a 10b5-1 plan indicates the sales were preplanned and intended to provide an affirmative defense against insider trading claims.

Key dependencies include the continued compliance with the 10b5-1 plan and any lock-up or transfer restrictions. Watch for subsequent Form 4s that disclose further conversions of Class B stock or additional plan-based trades over the next few reporting periods.

Market Impact Analyst

Large-dollar insider sales were executed at market prices well above the option strike.

The reported sale quantities total 10,000 shares at weighted average prices reported in ranges from approximately $316.79 to $329.19, implying gross proceeds in the multiple millions of dollars before fees (sale prices are explicitly provided as ranges in the footnotes). The exercise at $38.08 and immediate sales realize a large spread per share.

Investors may monitor trading volume and price action around 10/06/2025 and subsequent filings to gauge whether this was a one‑time liquidity event or part of an ongoing program; any further large insider sales would be material in the near term.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a 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). See Instruction 10.

1. Name and Address of Reporting Person^*

Hacker Severin

(Last) (First) (Middle)

C/O DUOLINGO, INC.

5900 PENN AVENUE

(Street)

PITTSBURGH PA 15206

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Duolingo, Inc. [ DUOL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	X	10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Tech Officer, Co-Founder

3. Date of Earliest Transaction (Month/Day/Year)
10/06/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock	10/06/2025		C		10,000	A	$38.08	10,072	D
Class A Common Stock	10/06/2025		S(1)		500	D	$317.3065(2)	9,572	D
Class A Common Stock	10/06/2025		S(1)		1,916	D	$318.264(3)	7,656	D
Class A Common Stock	10/06/2025		S(1)		1,599	D	$319.557(4)	6,057	D
Class A Common Stock	10/06/2025		S(1)		1,803	D	$320.333(5)	4,254	D
Class A Common Stock	10/06/2025		S(1)		1,173	D	$321.3906(6)	3,081	D
Class A Common Stock	10/06/2025		S(1)		109	D	$322.6239(7)	2,972	D
Class A Common Stock	10/06/2025		S(1)		300	D	$324.1047(8)	2,672	D
Class A Common Stock	10/06/2025		S(1)		500	D	$325.224(9)	2,172	D
Class A Common Stock	10/06/2025		S(1)		600	D	$326.4954(10)	1,572	D
Class A Common Stock	10/06/2025		S(1)		1,300	D	$327.4426(11)	272	D
Class A Common Stock	10/06/2025		S(1)		200	D	$328.755(12)	72	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (Right to Buy)	$38.08	10/06/2025		M			10,000	(13)	12/02/2030	Class B Common Stock	10,000	$0	35,252	D
Class B Common Stock	(14)	10/06/2025		C		10,000		(14)	(14)	Class A Common Stock	10,000	$0	96,075	D
Class B Common Stock	(14)	10/06/2025		C			10,000	(14)	(14)	Class A Common Stock	10,000	$0	86,075	D
Class B Common Stock	(14)							(14)	(14)	Class A Common Stock	2,886,917		2,886,917	I	See footnote(15)

Explanation of Responses:

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

2. 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 $316.79 to $317.72, 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.

3. 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 $317.87 to $318.84, 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.

4. 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 $318.97 to $319.96, 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.

5. 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 $319.98 to $320.95, 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.

6. 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 $321.00 to $321.78, 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.

7. 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 $322.00 to $322.68, 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.

8. 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 $323.61 to $324.49, 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.

9. 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 $324.78 to $325.62, 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.

10. 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 $326.01 to $326.94, 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.

11. 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 $327.02 to $327.92, 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.

12. 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 $328.32 to $329.19, 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.

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

14. 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.

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

Remarks:

	/s/ Stephen Chen, as Attorney-in-Fact for Severin Hacker	10/07/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did Severin Hacker (DUOL) report on 10/06/2025?

He exercised a 10,000-share option$38.08 and sold 10,000 Class A shares in multiple brokered transactions executed under a Rule 10b5-1 plan.

Were the sales by Severin Hacker part of a prearranged plan?

Yes. The sales were effected pursuant to a Rule 10b5-1 trading plan adopted on 9/11/2024, as disclosed in the Form 4.

How many Class A shares does Severin Hacker directly own after the reported transactions?

The Form 4 reports direct beneficial ownership of 72 Class A shares following the transactions.

Does the Form 4 disclose indirect holdings for Severin Hacker?

Yes. The filing reports 2,886,917 Class A shares held indirectly by the SBH Trust dated 3/10/2020, of which he is Trustee.

At what prices were the sold shares executed?

Footnotes disclose weighted average sale prices in ranges from $316.79 to $329.19; the broker calculated weighted averages are reported for each block.