PRME Prime Medicine, Inc. Insider Trading

10% Owner GV 2021 GP buys 1,500,000 shares at $3.30 in unprofitable biotech PRME; cluster of 3 other insiders buying within 14 days.

GV 2021 GP, a 10% shareholder, purchased 1,500,000 shares at $3.30 on 2025-08-01, expanding its stake by 85.1% to 3,262,440 shares (3.26M shares), a substantial commitment of $4,950,000.00 ($5.0M) in a company with a market cap of $573,756,763.98 ($573.8M). The company is unprofitable, reporting a net income of $-51,890,000.00 ($-51.9M) on quarterly revenue of $1,454,000.00 ($1.5M), indicating early-stage development with significant cash burn. The timing of this purchase aligns with a cluster pattern: 3 other insiders also bought within the past 14 days, suggesting coordinated alignment among company stakeholders on near-term value despite the company's loss position. The current price of $4.37 reflects a 30-day gain of +40.5% and a 90-day gain of +207.8%, though it remains -22.1% below the 52-week high of $5.61.

ARCH Venture Partners X bought 3,030,300 shares of PRME at $3.30 ($10.0M), boosting stake 94.7% to 6,230,300 shares

ARCH Venture Partners X, a 10% owner of Prime Medicine, purchased 3,030,300 shares at $3.30 on 2025-08-01 for $9,999,990.00, expanding its position from 3,200,000 to 6,230,300 shares. The company remains deeply unprofitable with a net loss of $-51,890,000.00 against minimal revenue of $1,454,000.00, though the stock has recovered +31.6% over 30 days and +140.5% over 90 days from a 52-week low. The prior ARCH purchase at this ticker on 2024-02-15 achieved positive returns at both the 30-day (+14.6%) and 90-day (+8.2%) intervals, establishing a successful historical precedent. A cluster of 3 other insiders also bought within the past 14 days, suggesting aligned investor interest despite the company's ongoing cash-burn profile.

Major VC fund ARCH Venture Partners XII acquired 3.03M shares of PRME for $10.0M at $3.30; now holds 6.23M (94.7% increase). Stock +31.6% in 30d, but -28.0% from 52w high.

ARCH Venture Partners XII, a 10% owner, purchased 3,030,300 shares at $3.30 on 2025-08-01 for $9,999,990.00, substantially increasing its stake to 6,230,300 shares post-transaction (94.7% increase from 3,200,000 pre-transaction shares). The insider's cross-ticker track record shows strong historical execution: 20 prior buys with an average 90-day return of +42.1% and a 100% win rate, and its sole prior PRME purchase on 2024-02-15 delivered an 8.2% 90-day return. However, PRME's fundamentals present a material headwind: the company generated only $1,454,000 in latest-quarter revenue against a net loss of $51,890,000, while the market cap stands at $530,429,594. The recent price momentum (+31.6% in 30 days) offers context, but against a 52-week high-to-current drawdown of -28.0% and sustained unprofitability, this large accumulation by a seasoned investor may reflect conviction—or a bet on an inflection in a pre-revenue or early-stage clinical program. A cluster of 3 other insiders buying within 14 days adds weight to the signal, though the company's capital burn rate and minimal revenue warrant close scrutiny on cash runway and path to profitability.

Director Nelsen Robert buys 3,030,300 shares of PRME at $3.30 (+94.7% to holdings); co-clustered buy pattern by 3 other insiders in 14 days.

Director Robert Nelsen purchased 3,030,300 shares of Prime Medicine at $3.30 on 2025-08-01, adding $10.0M in value and increasing his holdings by 94.7% from 3,200,000 shares to 6,230,300 shares. The purchase coincides with a cluster of 3 other insiders also buying within the past 14 days, suggesting coordinated confidence in near-term fundamentals. Nelsen's cross-ticker track record shows 4 prior buys with an average 90-day return of 56.4% and a 100% win rate; however, his single prior PRME purchase on 2024-02-15 achieved only 8.2% over 90 days, indicating less favorable outcomes at this specific ticker. Against headwinds of a $-51.9M net loss in the most recent full fiscal year and a current price of $4.04 that is 28.0% below the 52-week high of $5.61, this large-size buy by an insider with a strong historical record warrants investor attention to the company's clinical or operational inflection points that may underpin the conviction.

10% owner Liu buys 21,000 PRME shares at $2.52; stock now $2.73, -59.2% from 52-week high

Liu David R., a 10% owner of Prime Medicine, Inc., purchased 21,000 shares at $2.52 on 2025-06-30, increasing holdings from 20,219,945 to 20,240,945 shares. The company is unprofitable with net income of $-51,890,000.00 against revenue of $1,454,000.00 in its latest quarter, and the stock trades $2.73 (current) versus a 52-week high of $6.70, representing a -59.2% decline from peak. Within a 7-day window (2025-06-23 through 2025-06-30), Liu executed three consecutive buy transactions at PRME, each outcome remaining unmeasurable at both 30-day and 90-day horizons due to recency. Cross-ticker, Liu's track record shows 3 prior open-market buys but no documented well-timed outcomes at the 90-day mark.

10% owner Liu David R. buys 21,000 shares of PRME at $2.16; third consecutive buy in 9 days amid -67.8% drawdown from 52-week high.

Liu David R., a 10% shareholder, purchased 21,000 shares at $2.16 on 2025-06-23, representing a net increase of 21,000 shares (+0.1% vs pre-transaction holdings of 20.20M shares). This transaction is noteworthy as the third open-market buy by this insider at PRME within 9 calendar days (prior buys on 2025-06-16 and 2025-06-11). The purchase occurs at a price that is -67.8% below the 52-week high of $6.70, though the stock has recovered +67.4% over the preceding 30 days. The company remains unprofitable with net income of $-51.9M in its most recent full fiscal year and quarterly revenue of only $1.5M, presenting a context of financial distress despite the recent price rebound. The rapid sequence of accumulation by a major shareholder warrants attention to whether the insider views the recent 30-day appreciation as a sustained recovery or a tactical entry point in a deeply distressed biotech.

10% owner Liu David R. bought 21,000 shares of PRME at $1.49 on 2025-06-16, days after prior $1.49 purchase; stock -81.0% from 52-week high despite $196.9M market cap.

Liu David R., a 10% owner, purchased 21,000 shares at $1.49 on 2025-06-16, his second open-market buy in six days at the same price (prior buy on 2025-06-11 at PRME). The stock has deteriorated significantly, trading -81.0% from its 52-week high of $7.90 and down 5.7% over 30 days and 14.8% over 90 days. The company is fundamentally challenged: it reported revenue of $1,454,000.00 in its latest quarter against a net loss of $-51,890,000.00, and was unprofitable over its most recent full fiscal year. The rapid succession of purchases at an identical price point in a declining stock warrants attention to the underlying business trajectory and the owner's assessment of value at these levels.

10% owner Liu David R. acquired 21,000 shares of PRME at $1.60, stock now $1.46 (-81.5% from 52-week high)

Liu David R., a 10% owner of Prime Medicine, purchased 21,000 shares at $1.60 on 2025-06-11, increasing holdings to 20.18M shares. The stock has declined significantly, trading 81.5% below its 52-week high of $7.90, though it has recovered 15.0% over the past 30 days. The company reported a net loss of $51.9M against quarterly revenue of $1.5M, indicating a deeply unprofitable operation with a market cap of $191.7M. This buy by a major shareholder during a period of substantial stock weakness and ongoing losses warrants scrutiny of whether this reflects conviction in a turnaround or represents accumulation at an inflated valuation relative to fundamentals.

Prime Medicine CFO buys 20,000 shares at $1.19; stock down 84.7% from 52-week high amid cluster pattern of 2 other insider purchases.

Richard Brudnick, Chief Business Officer of Prime Medicine, purchased 20,000 shares at $1.19 on 2025-05-20, establishing an initial position. The timing follows a broader insider buying pattern: 2 other insiders also acquired shares within the past 14 days, forming a cluster buy. The purchase occurs amid significant price deterioration—the stock has fallen 84.7% from its 52-week high of $8.03 and has declined 58.5% over the past 90 days. The company remains operationally challenged, with a $-51.9M net loss in the most recent fiscal year against only $1.5M in quarterly revenue, limiting the fundamental case for valuation support. The convergence of multiple insider purchases at severely depressed levels warrants attention to whether management views the current price as an inflection point, though the company's negative earnings and revenue scale provide substantial execution risk.

CEO Reine Allan buys 125,000 shares at $1.18 as stock drops -84.7% from 52-week high; 2 other insiders buy simultaneously

Reine Allan, CEO of Prime Medicine, purchased 125,000 shares at $1.18 on 2025-05-21, establishing an initial position in a company generating $1.5M quarterly revenue but reporting $-51.9M net income. The stock has collapsed -84.7% from its 52-week high of $8.03 and is down -27.2% over the past 30 days, trading at $1.23 near the bottom of its annual range. This buy occurs as part of a cluster pattern where 2 other insiders also purchased shares within 14 days, suggesting coordinated accumulation at depressed absolute price levels. The timing—into steep momentum decline and against a backdrop of unprofitable operations—warrants examination of whether this reflects fundamental assessment of undervaluation or other strategic objectives driving the CEO and peer insiders simultaneously.