Form 4: Duolingo CTO Sells $3.2M in Stock Under 10b5-1 Plan

Duolingo Co-Founder and CTO Severin Hacker sold 10,000 shares of Class A Common Stock for approximately $3.2 million, following the exercise of stock options and conversion of Class B shares, all under a pre-arranged 10b5-1 trading plan.

Summary

• Severin Hacker, Duolingo's Co-Founder, Chief Technology Officer, Director, and 10% Owner, executed multiple transactions on October 6, 2025.
• Hacker exercised 10,000 stock options to acquire Class B Common Stock at an exercise price of $38.08 per share. These options were fully vested and exercisable.
• Concurrently, Hacker converted 20,000 shares of Class B Common Stock into Class A Common Stock.
• Following these acquisitions, Hacker sold a total of 10,000 shares of Class A Common Stock in multiple transactions at weighted average prices ranging from $317.3065 to $328.755 per share.
• The sales were executed pursuant to a Rule 10b5-1 trading plan adopted on September 11, 2024.
• The total proceeds from the sale of 10,000 Class A shares are approximately $3,203,000.
• After these transactions, Hacker directly holds 72 shares of Class A Common Stock and indirectly holds 2,886,917 shares of Class B Common Stock through the SBH Trust.

Sentiment

Score: 5

Explanation: The transactions represent a significant sale of shares by a key insider, which can be viewed with caution. However, the execution under a pre-arranged 10b5-1 plan suggests a planned diversification or liquidity event rather than a reaction to adverse company-specific news, making the sentiment neutral to slightly negative.

Positives

• The exercise of stock options indicates the reporting person is realizing value from vested equity.
• The high sale prices for Class A Common Stock (ranging from $317.3065 to $328.755) reflect a strong market valuation for Duolingo shares at the time of sale.
• The transactions were conducted under a Rule 10b5-1 trading plan, indicating pre-planned sales rather than a reaction to immediate market conditions.

Negatives

• Significant insider selling by a co-founder and CTO could be perceived negatively by some investors, potentially signaling a desire to diversify holdings.
• The reduction in direct Class A Common Stock ownership by a key executive.

Future Outlook

NA

Industry Context

NA

Related Party Transactions

• Severin Hacker's indirect ownership of 2,886,917 Class B Common Stock through the SBH Trust dated March 10, 2020, is a related party holding.

Stakeholder Impact

• Shareholders: May interpret the insider sale as a signal, potentially leading to short-term price volatility. However, the 10b5-1 plan context may temper concerns.

Key Dates

Recommendation

While the sale by a co-founder and CTO is substantial, it was executed under a pre-arranged 10b5-1 plan, which typically indicates a planned financial event rather than a reaction to new, negative company information. The high sale prices reflect strong market performance. Investors should monitor future insider activity and company performance, but this specific filing does not present a strong 'buy' or 'sell' signal on its own, warranting a 'hold' position.

Keywords

Duolingo, DUOL, Severin Hacker, Insider Trading, Form 4, Stock Sale, Stock Option Exercise, 10b5-1 Plan, Class A Common Stock, Class B Common Stock, CTO, Co-Founder