DUOL Form 4: Hacker exercises $38.08 option, sells 10,000 shares under 10b5-1 plan

Rhea-AI Filing Summary

Severin Hacker, Duolingo Chief Technology Officer and co-founder, reported option exercise and planned sales under a Rule 10b5-1 plan. The filing shows a $38.08 stock option exercised to acquire 10,000 shares on 09/19/2025. Those 10,000 shares were subsequently sold in multiple transactions under a 10b5-1 plan adopted September 11, 2024, for weighted-average prices reported in five separate sale groups ranging from about $286.26 to $291.15, generating aggregate sales of 10,000 shares. After the option exercise and sales, the reporting person shows 72 shares of Class A common stock directly owned and larger holdings of Class B and indirect holdings, including 2,886,917 Class A-equivalent shares held indirectly through the SBH Trust (Reporting Person is trustee).

Positive

• Sale executed under a Rule 10b5-1 trading plan, which is disclosed and can reduce concerns about selective insider timing
• Full disclosure of weighted-average sale price ranges and willingness to provide per-trade detail enhances transparency
• Significant indirect holdings remain (2,886,917 Class A-equivalent shares held in SBH Trust), indicating retained long-term economic interest

Negative

• Reporting Person sold 10,000 shares following option exercise, reducing direct public Class A ownership to 72 shares
• Realized gains are potentially material given the strike price ($38.08) and sale prices (~$286–$291), which could be viewed as monetizing equity

Insights

Corporate Governance Expert

TL;DR: Insider exercised low-strike options and sold all resulting shares through a pre-established 10b5-1 plan; trust holdings remain substantial.

The filing documents a standard insider liquidity event: exercise of a fully vested option at $38.08 followed by sales executed under a Rule 10b5-1 plan, minimizing timing concerns about selective trading. The disclosures provide weighted-average sale prices for five sale tranches, covering price ranges between $286.26 and $291.15, and confirm the Reporting Person will provide per-trade breakdowns on request. Direct public float exposure now appears minimal (72 Class A shares), while substantial economic interest remains via Class B shares and the SBH Trust (2,886,917 Class A-equivalent shares), preserving control-related alignments.

Securities/Compensation Analyst

TL;DR: Option exercise at a low strike and immediate sales realize significant gains; disclosures are complete and procedural.

The exercise of a $38.08 option and subsequent sales at ~ $286–$291 represent a material spread per share realized by the reporting person, but the transactions were executed under a 10b5-1 plan adopted in 2024, which is disclosed in the filing. The filing lists total shares sold as 10,000 and shows resulting direct Class A ownership of 72 shares. Derivative and indirect holdings (including Class B shares convertible into Class A and trust-held shares) indicate continued long-term stake. The filing is informational and routine from a compensation-liquidity perspective.

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)
09/19/2025

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	09/19/2025		C		10,000	A	$38.08	10,072	D
Class A Common Stock	09/19/2025		S(1)		1,300	D	$286.7732(2)	8,772	D
Class A Common Stock	09/19/2025		S(1)		2,300	D	$287.8146(3)	6,472	D
Class A Common Stock	09/19/2025		S(1)		2,300	D	$288.8122(4)	4,172	D
Class A Common Stock	09/19/2025		S(1)		1,900	D	$289.7897(5)	2,272	D
Class A Common Stock	09/19/2025		S(1)		2,200	D	$290.7845(6)	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	09/19/2025		M			10,000	(7)	12/02/2030	Class B Common Stock	10,000	$0	45,252	D
Class B Common Stock	(8)	09/19/2025		C		10,000		(8)	(8)	Class A Common Stock	10,000	$0	96,075	D
Class B Common Stock	(8)	09/19/2025		C			10,000	(8)	(8)	Class A Common Stock	10,000	$0	86,075	D
Class B Common Stock	(8)							(8)	(8)	Class A Common Stock	2,886,917		2,886,917	I	See footnote(9)

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 $286.26 to $287.25, 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.

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 $287.27 to $288.23, 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 $288.28 to $289.27, 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 $289.32 to $290.30, 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.

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 $290.43 to $291.15, 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 shares subject to the option are fully vested and exercisable.

8. 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.

9. 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	09/22/2025
	** 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 did Severin Hacker report on the Form 4 for DUOL?

He exercised a stock option to buy 10,000 shares at $38.08 and sold 10,000 shares on 09/19/2025 under a Rule 10b5-1 plan.

How many shares were sold and at what prices according to the filing?

10,000 shares were sold across multiple transactions with weighted-average sale prices reported in five tranches, with per-trade price ranges between $286.26 and $291.15.

Does the filing indicate the sale was pre-planned or opportunistic?

The sales were effected pursuant to a Rule 10b5-1 trading plan adopted on September 11, 2024, as stated in the filing.

What is Severin Hacker's remaining ownership after these transactions?

Direct Class A ownership is shown as 72 shares; the filing also discloses Class B holdings and 2,886,917 Class A-equivalent shares held indirectly through the SBH Trust.

Are the exercised options vested and exercisable?

Yes; the filing states the shares subject to the option are fully vested and exercisable.