Form 4: Duolingo Co-Founder Sells Shares Under 10b5-1 Plan

Duolingo Co-Founder and CTO Severin Hacker executed a series of stock option exercises and subsequent sales of Class A Common Stock totaling 10,000 shares under a pre-arranged 10b5-1 trading plan.

Summary

• Severin Hacker, Duolingo's Co-Founder, Chief Technology Officer, Director, and 10% Owner, reported transactions on September 19, 2025.
• Hacker exercised a stock option to acquire 10,000 shares of Class A Common Stock at an exercise price of $38.08 per share.
• A total of 10,000 shares of Class A Common Stock were sold in multiple transactions under a Rule 10b5-1 trading plan adopted on September 11, 2024.
• The sales occurred at weighted average prices ranging from $286.7732 to $290.7845.
• Following these transactions, Hacker's direct beneficial ownership of Class A Common Stock is 72 shares.
• Hacker also directly holds 45,252 stock options and 96,075 shares of Class B Common Stock, with an additional 2,886,917 shares of Class B Common Stock held indirectly through the SBH Trust.

Sentiment

Score: 5

Explanation: The transactions represent routine diversification and liquidity management by a key executive, executed under a pre-established 10b5-1 trading plan, which mitigates concerns about discretionary insider selling. The executive retains substantial ownership in the company.

Positives

• The transactions were executed pursuant to a Rule 10b5-1 trading plan, indicating pre-planned, non-discretionary trading and reducing concerns about opportunistic insider selling.
• The exercise of stock options at $38.08 per share and subsequent sales at prices ranging from $286.26 to $291.15 demonstrate significant unrealized gains for the executive.

Negatives

• The sale of 10,000 shares by a co-founder and CTO, even if pre-planned, could be perceived negatively by some investors, potentially leading to short-term market uncertainty.

Risks

• The sale of a significant number of shares by a co-founder and CTO, even under a pre-planned 10b5-1 program, could be interpreted negatively by investors, potentially impacting market sentiment.

Future Outlook

N/A

Management Comments

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

Industry Context

N/A

Related Party Transactions

• 2,886,917 shares of Class B Common Stock are held indirectly by Severin Hacker through the SBH Trust dated March 10, 2020, of which he is the Trustee.

Stakeholder Impact

• Shareholders: May interpret the insider selling as a signal, potentially leading to short-term price volatility, though the 10b5-1 plan mitigates some concerns.
• Reporting Person (Severin Hacker): Has diversified a portion of his personal holdings and realized gains from vested stock options.

Key Dates

Recommendation

The transactions by Duolingo's Co-Founder and CTO, Severin Hacker, involved the exercise of stock options and subsequent sale of 10,000 Class A Common Stock shares under a pre-arranged Rule 10b5-1 trading plan. While the sales were significant, the pre-planned nature mitigates immediate concerns of a negative signal on company fundamentals. The executive retains substantial indirect ownership. Investors should maintain a 'hold' position, monitoring future company performance and market developments rather than reacting solely to this planned insider transaction.

Keywords

Duolingo, DUOL, Severin Hacker, insider trading, Form 4, stock option, share sale, 10b5-1 plan, CTO, co-founder, beneficial ownership