Brian S Posner

Director Brian S Posner buys 2,000 shares of DYN at $16.94; cross-ticker avg 90d return +72.2%, but DYN fundamentals show $-120.9M net loss

Brian S Posner (Director) purchased 2,000 shares at $16.94 on 2026-06-08, bringing his non-derivative holdings to 24,500 shares, a net addition of 8.9% to pre-transaction holdings. His cross-ticker track record shows 6 prior open-market buys with an average 90-day return of +72.2% and a 90-day win rate of 83.33%, establishing a strong pattern of well-timed purchases across multiple securities. At DYN specifically, his 5 prior trades show 4 of 5 well-timed at the 90-day mark, though recent outcomes have been modest: the most recent buy on 2026-05-26 returned +1.1% over 90 days, while the May 20 purchase returned +7.5% over 90 days. The company remains fundamentally unprofitable with a net loss of $-120.9M for its most recent full fiscal year, creating tension between the insider's historical acumen in equity selection and the underlying financial distress of the target. The insider retains 35,152 shares of derivative holdings (stock options) after this transaction, indicating an ongoing exposure to DYN beyond the current purchase.

Director Posner buys 2.5K DYN shares at $17.48; holdings rise to 22.5K. 4 of 5 prior same-ticker buys well-timed; 90d win rate 83.33% cross-ticker.

Brian S Posner purchased 2,500 shares at $17.48 on 2026-06-03, growing his position to 22.5K shares (+12.5% from prior holdings). The stock has fallen -31.8% from its 52-week high of $25.00 and is currently at $17.04, down -9.6% over 30 days. Across his cross-ticker open-market history, Posner's 6 prior buys averaged +76.7% return in 30 days and +72.2% in 90 days, with an 83.33% win rate at 90 days. At DYN specifically, he has demonstrated a consistent pattern: 4 of his 5 prior trades at this ticker proved well-timed at the 90-day mark, including his most recent buy on 2026-05-26 (which posted +1.1% in 30 and 90 days). The company reported net income of $-120.9M over its most recent full fiscal year, underscoring the unprofitable status of the underlying business. This buy adds signal weight given his prior success at this specific ticker, though the company's negative profitability and the recent 30-day decline warrant evaluation of whether the market repricing reflects material changes.

Director Brian S Posner bought 2,000 shares of Dyne Therapeutics (DYN) at $18.21 on 2026-05-26, raising holdings to 20,000 shares despite -$120.9M net income.

Brian S Posner, Director of unprofitable Dyne Therapeutics (net income: -$120,854,000.00), purchased 2,000 shares at $18.21, expanding his stake by 11.1% to 20,000 shares. His cross-ticker track record shows strong execution: 4 prior open-market buys averaged +112.9% 30-day return and +101.6% 90-day return with a 75.00% 90-day win rate. At DYN specifically, however, his timing pattern is mixed: 2 of his 3 prior DYN purchases delivered positive 90-day returns, but the most recent buy on 2026-03-30 returned only +1.9% over 30 days, and his March 11 purchase lost -10.2% over 90 days. The current stock price of $18.56 sits -25.8% from its 52-week high of $25.00 but has recovered +18.8% over the past 90 days, suggesting some stabilization after earlier declines. This purchase signals director confidence in the near-term trajectory, though the company's continued unprofitability and mixed recent timing outcomes at this ticker warrant attention.

Director Brian S Posner buys 2,500 DYN shares at $17.12; 2 of 3 prior DYN buys showed positive 90-day returns.

Director Brian S Posner purchased 2,500 shares at $17.12 on 2026-05-20, increasing his holdings to 18,000 shares (+16.1% net change). His prior transaction history at Dyne Therapeutics shows mixed results: 2 of his 3 prior DYN buys generated positive 90-day returns (+1.7% and +15.3%), though one underperformed (-10.2%). His cross-ticker track record demonstrates stronger timing with 75.00% win rate and avg 90d return +101.6%, but this current purchase arrives as the stock trades at -30.5% from its 52-week high and -11.7% over the past 30 days. The company remains unprofitable with net income of $-120.9M over its most recent fiscal year, which limits visibility into whether this buy reflects conviction in a recovery or operational turnaround.

Posner (Director) buys 2,000 shares of DYN at $17.08; third DYN purchase in three weeks as stock trades 30.2% above 52-week low.

Director Brian S Posner purchased 2,000 shares at $17.08 on 2026-03-30, bringing his total holdings to 15,500 shares, representing a 14.8% increase in his position. This marks his third open-market purchase of DYN in 19 days (prior buys on 2026-03-11 and 2026-03-06), suggesting sustained accumulation despite the company's unprofitable status with net income of $-108.0M over its most recent full fiscal year. The current stock price of $18.10 sits 30.2% above the 52-week low of $6.81, positioning these recent purchases well into a recovery phase rather than at depressed valuations. While Posner's cross-ticker track record shows strong historical execution with 100.00% win rate and average 90d return of +399.7%, the measurable outcomes from his three recent DYN purchases remain unavailable, and the pattern warrants observation as the company remains unprofitable despite recent price appreciation.

Director Posner buys 2,000 shares of DYN at $19.35, increasing stake to 13.5K shares; stock now at $17.92, -26.2% from 52-week high.

Brian S. Posner, a Director of Dyne Therapeutics, purchased 2,000 shares at $19.35 on 2026-03-11, boosting his holdings from 11.5K to 13.5K shares (+17.4% increase in stake). The company is unprofitable with a net loss of $108.0M over its most recent fiscal year. The current stock price of $17.92 sits -26.2% from the 52-week high of $24.29, though it is up 7.4% over the past 30 days. This buy occurred just five days after a prior DYN purchase on 2026-03-06, suggesting consecutive accumulation in the same ticker. Posner's cross-ticker historical record shows strong 90-day returns (average +399.7% with 100% win rate across 2 prior buys), but this provides limited predictive value for Dyne specifically, where prior outcomes are not yet measurable. The pattern of multiple discrete buys in rapid succession warrants attention as a measure of shareholder commitment during a period when the stock is trading below recent peaks.

Director Posner buys 3,000 shares of DYN at $15.06; holds 11,500 post-transaction as stock trades $19.78, +17.7% in 30 days.

Director Brian S Posner purchased 3,000 shares at $15.06 on 2026-03-06, expanding his holdings by 35.3% to 11,500 shares. The stock has appreciated 17.7% over the 30 days following the transaction, currently trading at $19.78. Despite the positive recent price movement, Dyne Therapeutics posted a net income of $-108.0M in its most recent full fiscal year, indicating ongoing operational losses. Posner's cross-ticker track record shows 100.00% win rate on prior buys with avg 90d return of +399.7%, though this transaction represents only his second recorded open-market purchase and his first at this ticker, so historical performance context is limited.

Director Brian S Posner buys 1,000 ACGL shares at $17.34 on 2025-08-01; holdings rise to 5,000 shares (+25.0%).

Director Posner purchased 1,000 shares at $17.34, increasing his holdings from 4,000 to 5,000 shares (+25.0% growth in position size). The transaction occurred when ARCH CAPITAL trades at $88.51, well below its 52-week high of $114.86 (-22.9%). The company reports strong fundamentals: annual revenue growth of +27.9%, a P/E of 8.81, and quarterly net income of $574.0M on $4.7B in revenue. This represents a modest but material accumulation by a director during a period of price weakness relative to the 52-week range, though the stock has declined only -0.8% over 30 days and -4.8% over 90 days.