Hacker Severin

CTO Hacker Severin sells 10,000 DUOL shares for $1.7M via 8 transactions; stock down 47.1% in 30 days

Hacker Severin, Chief Technology Officer and Co-Founder, executed 8 separate sales on 2025-11-19 totaling 10,000 shares for $1,727,441.09, reducing his position from 10,072 shares to 72 shares post-transaction. The blended average sale price of $172.74 contrasts sharply against the current price of $168.01 and a 52-week high of $540.68, indicating the stock has declined 68.9% from its peak and 47.1% over the past 30 days. Severin's cross-ticker track record shows 20 prior sells averaging -44.5% return over 30 days, though his prior same-ticker activity at DUOL (5 recent sales on 2025-11-04) does not yet have measurable outcomes. The filing contains a derivative-conversion component, meaning his actual residual position extends beyond the 72 shares reflected in Table I.

CTO Hacker Severin sells 10,000 shares ($2.6M) at $263.13 avg; stock now -64.2% from 52-week high

On 2025-11-04, Hacker Severin, Chief Tech Officer and Co-Founder of Duolingo, filed a Form 4 reporting 10 separate sales totaling 10,000 shares for $2,631,299.19 at prices ranging from $257.92 to $266.12, with a blended average of $263.13. This represents a sale of 99.3% of his pre-transaction holdings, leaving only 72 shares post-trade. The timing is material: the stock is currently trading at $193.74, down 64.2% from its 52-week high of $540.68 and down 39.4% over the preceding 30 days. His cross-ticker historical track record shows an average 30-day return of -18.8% following prior sales, and he executed five prior sales at DUOL on 2025-10-20 (outcomes not yet measurable). The large concentrated sale by a co-founder and CTO at elevated prices, followed by a sharp reversal in stock price, raises questions about information asymmetry and timing, particularly given the recent prior sales at this same ticker and the company's strong fundamentals (annual revenue growth of 40.8%, P/E of 8.35).

CTO Hacker Severin sold 10,000 DUOL shares for $3.1M on 2025-10-20; 99.3% position reduction to 72 shares

Hacker Severin (Chief Tech Officer, Co-Founder) executed 15 separate sales totaling 10,000 shares for $3,147,198.32 on 2025-10-20, reducing his holdings from 10,072 shares to 72 shares—a 99.3% reduction. The sales occurred across a range of prices from $305.86 to $324.10, with a blended average of $314.72. This represents a near-complete liquidation of his open-market position, though derivative holdings in Form 4 Table II may represent additional exposure not yet populated in our database. The transaction occurred as DUOL trades 43.1% below its 52-week high of $540.68 and 90 days after recent sales on 2025-10-06 (outcomes not yet measurable). His cross-ticker track record shows 20 prior sells with an average 30-day return of +15.9%, indicating historical ability to time sales, though this metric does not extend to his same-ticker history at DUOL.

CTO Hacker Severin sold 10,000 shares (10.0K shares) for $3.2M at blended $321.63, leaving 72 shares held. Derivative conversion flagged.

Hacker Severin, Chief Technology Officer and Co-Founder, executed 11 separate sales totaling 10,000 shares for $3,216,303.32 on 2025-10-06 at prices ranging from $317.31 to $328.76. The filing contains a derivative-conversion notation, indicating the disposition involves conversion of derivative securities; the insider's full position exposure (including any remaining derivative holdings) is not fully reflected in the Table I share count of 72 shares post-transaction. This transaction reduced his direct shareholding by 99.3% relative to pre-transaction holdings of 10,072 shares. The company trades at a P/E of 45.45 with revenue growth of 40.8% year-over-year, and the stock has declined 40.8% from its 52-week high of $540.68 despite a 30-day gain of 18.0%. His cross-ticker track record across 20 prior open-market sales shows a 2.6% average 30-day return, though prior same-ticker outcomes at DUOL remain immeasurable. Investors should monitor the derivative holdings disclosure when fully populated to assess the true scope of position change.

CTO Hacker Severin sold 10,000 shares of DUOL for $2.9M on 2025-09-19, reducing stake from 10.1K to 72 shares.

Hacker Severin, Chief Technology Officer and Co-Founder of Duolingo, executed 5 separate sales totaling 10,000 shares for $2,889,373.13 at prices ranging from $286.77 to $290.78, leaving only 72 shares post-transaction. This represents a reduction of -99.3% vs pre-transaction holdings, though per the derivative-conversion flag, this filing reflects conversion of derivative securities and the Table I shares_after figure (72 shares) may not represent the insider's total position across derivative and equity holdings combined. The transactions occurred on 2025-09-19 when DUOL was trading near $309.34 current price; the stock has declined -26.8% over the prior 90 days and -6.8% over the trailing 30 days, trading -42.8% below its 52-week high of $540.68. Severin's cross-ticker track record spans 20 prior sells with an average 90-day return of -17.2%, while his prior sales at DUOL on 2025-09-05 (4 transactions) remain too recent to measure outcomes. The company's fundamentals show strong revenue growth of +40.8% annually and a P/E of 43.94, though the stock's recent weakness and Severin's near-complete open-market liquidation merit investor scrutiny given his founder-level influence on product and strategy.

Duolingo CTO Hacker Severin sold 10,000 shares for $2.7M in 8 transactions on 2025-09-05; retains 72 shares post-transaction.

Hacker Severin, Chief Tech Officer and Co-Founder, executed 8 separate sales totaling 10,000 shares for $2,685,461.75 at a blended average price of $268.55 on 2025-09-05. This represents a -99.3% reduction of his pre-transaction holdings, leaving him with only 72 shares. The timing is notable: Severin's prior 20 open-market sells across all tickers averaged a 30-day return of -20.4%, and DUOL shares have declined -26.2% over the past 30 days and -42.3% over 90 days from a 52-week high of $540.68. At DUOL specifically, he conducted 5 prior sells on 2025-08-19 (outcomes not yet measurable), suggesting recent sustained selling activity at the company. The company fundamentals remain relatively strong (revenue $252.3M, net income $44.8M, annual growth +40.8%, P/E 38.85), but the magnitude and concentrated timing of this near-total reduction in his position, combined with his cross-ticker sell history averaging negative 30-day returns, may warrant investor attention to any broader context around the sale.

Hacker Severin (CTO, Co-Founder) sells 10,000 shares for $3.4M across 17 transactions, reducing DUOL stake by 99.3%

On 2025-08-19, Hacker Severin executed 17 separate sales totaling 10,000 shares for $3,445,587.09 at prices ranging from $339.15 to $359.30, with a blended average price of $344.56. This reduction from 10,072 shares to 72 shares represents a 99.3% reduction in his DUOL holdings. The filing contains a derivative-conversion transaction (Table II not yet populated), so the 72 shares remaining represent only the open-market equity portion and do not reflect his complete economic interest. The stock has since declined 3.0% over 30 days and 33.6% over 90 days from the sale dates, trading at $345.52 with a P/E of 49.08. While company fundamentals remain strong (revenue growth of 40.8% and net income of $44.8M), the timing of this large staged liquidation of open-market shares—by a technical co-founder—warrants scrutiny of whether derivative holdings or other compensation structures factor into this significant reduction.

Co-Founder/CTO Hacker Severin sold 10,000 shares at blended avg $344.41, reducing stake by 99.3% to 72 shares post-transaction

Hacker Severin, Chief Tech Officer and Co-Founder of Duolingo, executed 12 separate sales totaling 10,000 shares for $3,444,076.39 on 2025-08-05, reducing his holdings from 10,072 shares to 72 shares. The transaction occurred at prices ranging from $339.32 to $354.45 per share, with a blended average of $344.41, while the stock currently trades at $390.84 (13.5% above the transaction prices). Severin has a cross-ticker track record of 20 prior sells with an average 30-day return of -12.5%, and recently executed multiple sales at the same ticker on 2025-07-21, signaling a pattern of ongoing liquidation activity. The sale is material in scale and timing but occurs in a high-growth company (P/E 55.52, +40.8% annual revenue growth) where the current price has appreciated significantly from the execution levels, raising questions about execution strategy and forward-looking sentiment from a co-founder.

CTO Severin executes 13 separate sales totaling 10,000 shares for $3,603,336.34 on 2025-07-21, reducing stake by 99.3%

Hacker Severin (Chief Tech Officer, Co-Founder) executed 13 separate sales totaling 10,000 shares for $3,603,336.34 on 2025-07-21, reducing his DUOL holdings from 10,072 shares to 72 shares. This represents a 99.3% reduction of his pre-transaction position. The sales occurred at prices ranging from $355.31 to $370.05 per share (blended average $360.33), at a time when DUOL is trading 34.1% below its 52-week high of $540.68 and has declined 24.5% over the past 30 days. The filing contains a derivative-conversion transaction, meaning his full economic position may not be captured solely by the Table I share count. Across Severin's cross-ticker sell history, prior sells have averaged a negative 30-day return of -21.5%, though his 5 prior sales at DUOL on 2025-07-07 (just two weeks prior) do not yet have measurable outcomes and offer limited insight into timing patterns at this specific security.

Co-Founder CTO Hacker Severin sells 10,000 shares of DUOL for $3.9M at $392.89 blended avg

Hacker Severin executed 9 separate sales totaling 10,000 shares for $3,928,885.17 on 2025-07-07, reducing his holdings from 10,072 shares to 72 shares. This represents a 99.3% reduction in his disclosed position. The sales occurred at prices ranging from $386.90 to $396.73, with a blended average of $392.89, against a current price of $390.75 and a 52-week high of $540.68. The stock has declined 27.7% from its 52-week high and 21.5% over the prior 30 days. Note that this filing is flagged for derivative-conversion activity; the Form 4 Table II derivative securities have not yet populated in the database, so the 72 shares shown post-transaction may not represent the insider's full economic position. Across his cross-ticker open-market history, Severin's 20 prior sells averaged -25.4% 90-day returns, indicating a pattern of selling ahead of subsequent declines.