Duolingo insider plans $5.3M stock sale

Form 144 reports a planned sale of up to 37,366 Duolingo common shares by an affiliated holder via stock option exercise.

Rhea-AI Filing Summary

Duolingo, Inc. (DUOL) has a notice of proposed sale of securities filed on behalf of Luis Von Ahn Arellano for up to 37,366 shares of common stock. The shares are to be sold on or after September 21, 2026 through Morgan Stanley Smith Barney, following acquisition via exercise of stock options for cash.

The filing also lists recent Rule 10b5-1 plan sales on September 16, 2026 of 28,292 shares of common stock for Luis Von Ahn Arellano and 19,008 shares for the Luis Von Ahn Foundation, with stated aggregate sale values.

Key Figures

Shares proposed for sale: 37,366 shares Estimated aggregate market value of proposed sale: $5,302,235.40 10b5-1 sale shares for Luis Von Ahn Arellano: 28,292 shares +3 more

6 metrics

Shares proposed for sale 37,366 shares Common stock covered by the Form 144 notice for Luis Von Ahn Arellano

Estimated aggregate market value of proposed sale $5,302,235.40 Value associated with the 37,366 Duolingo common shares in the notice

10b5-1 sale shares for Luis Von Ahn Arellano 28,292 shares Common shares sold on September 16, 2026 under a 10b5-1 plan

10b5-1 sale value for Luis Von Ahn Arellano $4,250,140.24 Aggregate sale value for 28,292 shares on September 16, 2026

10b5-1 sale shares for Luis Von Ahn Foundation 19,008 shares Common shares sold on September 16, 2026 for the foundation

10b5-1 sale value for Luis Von Ahn Foundation $2,832,624.09 Aggregate sale value for 19,008 shares on September 16, 2026

Key Terms

Rule 144, Form 144, 10b5-1, Exercise of Stock Options, +1 more

5 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Form 144 regulatory

"144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

10b5-1 regulatory

"10b5-1 Sales for LUIS VON AHN ARELLANO"

A 10b5-1 plan is a pre-set schedule that lets company insiders buy or sell shares according to written instructions made when they do not possess material, nonpublic information. Think of it as a timed automatic payment for stock trades: it helps insiders avoid accusations of trading on secret information and gives outside investors a clearer signal about whether sales are routine or potentially informative about the company’s prospects.

Exercise of Stock Options financial

"Exercise of Stock Options | Issuer"

aggregate market value financial

"| 37366 | 5302235.40 | 40387012 | 09/21/2026 |"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing disclose for Duolingo, Inc. (DUOL)?

It discloses that 37,366 shares of Duolingo common stock may be sold for the account of Luis Von Ahn Arellano, with the shares to be acquired via exercise of stock options for cash and sold through Morgan Stanley Smith Barney on or after September 21, 2026.

How many Duolingo (DUOL) shares are proposed to be sold under this Form 144?

The notice covers a proposed sale of up to 37,366 shares of Duolingo common stock. The filing also reports an estimated aggregate market value of $5,302,235.40 for these shares at the time of the notice.

What is the planned method for acquiring the Duolingo (DUOL) shares before sale?

The shares covered by the notice are to be acquired through the exercise of stock options, with the consideration described as cash. After exercise, the shares may be sold in the market in reliance on Rule 144.

When are the Duolingo (DUOL) shares expected to be sold under this notice?

The proposed sale date listed is September 21, 2026. Form 144 is a notice of intent; it does not guarantee that all or any of the 37,366 shares will actually be sold on that date.

What prior 10b5-1 plan sales related to Duolingo (DUOL) are disclosed?

The filing notes Rule 10b5-1 sales on September 16, 2026: 28,292 shares of common stock sold for $4,250,140.24 for Luis Von Ahn Arellano, and 19,008 shares sold for $2,832,624.09 for the Luis Von Ahn Foundation.

Which broker is named for the proposed Duolingo (DUOL) share sale?

The broker listed is Morgan Stanley Smith Barney LLC Executive Financial Services, with an address at 1 New York Plaza, 8th Floor, New York, NY 10004, as the firm through which the 37,366 Duolingo common shares may be sold.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/21/2026 - 04:33 PM Accepted by SEC EDGAR 09/21/2026 - 04:31 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001829259
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Duolingo, Inc.
SEC File Number	001-40653
Address of Issuer	5900 Penn Avenue Pittsburgh PENNSYLVANIA 15206
Phone	4125676602
Name of Person for Whose Account the Securities are To Be Sold	LUIS VON AHN ARELLANO
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director
Relationship to Issuer	Officer
Relationship to Issuer	10% Stockholder

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	37366	5302235.40	40387012	09/21/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	09/21/2026	Exercise of Stock Options	Issuer			37366	09/21/2026	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
10b5-1 Sales for LUIS VON AHN ARELLANO 5900 Penn Avenue Pittsburgh PA 15206	Common	09/16/2026	28292	4250140.24
10b5-1 Sales for LUIS VON AHN FOUNDATION 5900 Penn Avenue Pittsburgh PA 15206	Common	09/16/2026	19008	2832624.09

144: Remarks and Signature

Remarks
Date of Notice	09/21/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	06/02/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Luis Von Ahn Arellano
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)