Duolingo 4: CEO sold all 110K shares for $16.7M (Oct 9, 2026)

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-10-07 10b5-1 Pre-arranged Plan: Yes --- Issuer --- Name: Duolingo, Inc. (DUOL) CIK: 0001562088 --- Reporting Owner --- Name: von Ahn Luis CIK: 0001829259 Role: Director, Officer (President & CEO, Co-Founder), 10%+ Owner --- Non-Derivative Transactions --- [Transaction #1] Security: Class A Common Stock Date: 2026-10-07 | Code: C (Conversion of derivative) Shares: +110,046 | Price: $38.08 Total Value: $4,190,551.68 Shares Owned After: 110,046 | Ownership: D (Direct) [Transaction #2] Security: Class A Common Stock Date: 2026-10-07 | Code: S (Open market sale) Shares: -20,025 | Price: $150.63 Total Value: $3,016,403.80 Shares Owned After: 90,021 | Ownership: D (Direct) Footnotes: [F1] The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 2, 2026. [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 $150.00 to $150.99, 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. [Transaction #3] Security: Class A Common Stock Date: 2026-10-07 | Code: S (Open market sale) Shares: -55,036 | Price: $151.52 Total Value: $8,339,285.87 Shares Owned After: 34,985 | Ownership: D (Direct) Footnotes: [F1] The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 2, 2026. [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 $151.00 to $151.99, 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. [Transaction #4] Security: Class A Common Stock Date: 2026-10-07 | Code: S (Open market sale) Shares: -29,871 | Price: $152.47 Total Value: $4,554,532.93 Shares Owned After: 5,114 | Ownership: D (Direct) Footnotes: [F1] The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 2, 2026. [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 $152.00 to $152.99, 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. [Transaction #5] Security: Class A Common Stock Date: 2026-10-07 | Code: S (Open market sale) Shares: -5,114 | Price: $153.26 Total Value: $783,777.27 Shares Owned After: 0 | Ownership: D (Direct) Footnotes: [F1] The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 2, 2026. [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 $153.00 to $153.61, 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. --- Derivative Transactions --- [Transaction #1] Security: Stock Option (Right to Buy) Date: 2026-10-07 | Code: M (Exercise of derivative) Shares: -110,046 | Price: $0.00 Exercise Price: $38.08 Exercisable: N/A | Expires: 2030-12-02 Shares Owned After: 0 | Ownership: D (Direct) Footnotes: [F6] The options are fully vested and exercisable. [Transaction #2] Security: Class B Common Stock Date: 2026-10-07 | Code: C (Conversion of derivative) Shares: +110,046 | Price: $0.00 Shares Owned After: 3,478,166 | Ownership: D (Direct) Footnotes: [F7] 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. [F7] 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. [F7] 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. [Transaction #3] Security: Class B Common Stock Date: 2026-10-07 | Code: C (Conversion of derivative) Shares: -110,046 | Price: $0.00 Shares Owned After: 3,368,120 | Ownership: D (Direct) Footnotes: [F7] 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. [F7] 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. [F7] 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. --- Footnotes (Complete Index) --- F1: The sale was effected pursuant to the Reporting Person's Rule 10b5-1 trading plan adopted on June 2, 2026. 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 $150.00 to $150.99, 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 $151.00 to $151.99, 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 $152.00 to $152.99, 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 $153.00 to $153.61, 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 options are fully vested and exercisable. F7: 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. --- Signature --- /s/ /s/ Stephen Chen, as Attorney-in-Fact for Luis von Ahn (2026-10-09)