Peter Kolchinsky

RA Capital director bought 160,354 shares (160.4K) at $8.93–$8.95 on July 16–17, expanding stake to 16.98M shares amid -27.0% 90-day decline.

RA Capital Management, LP purchased 2 separate tranches totaling 160,354 shares for $1,432,118.86 over July 16–17, increasing its stake by 1.0% to 16.98M shares. This represents the director's fifth consecutive buy at Artiva in June–July 2026, showing sustained accumulation despite significant recent price weakness: the stock is down 27.0% over 90 days and -37.0% from its 52-week high of $14.53, trading at $9.15. The company's fundamentals remain deeply challenged—$251.0K quarterly revenue, -$23.5M net income, -100.0% annual revenue growth, and unprofitable status—making valuation compression a material concern. While the insider's broader cross-ticker track record shows 20 prior buys with an average 30-day return of +16.6%, the prior four buys at this ticker have not yet reached measurable 90-day outcomes, and the only measurable same-ticker result (June 12 buy) shows a modest +12.5% 30-day gain that has not yet proven durable.

RA Capital Management bought 21,654 shares at blended avg $8.96; holdings now 16.82M shares at ARTV

RA Capital Management executed 2 separate purchases totaling 21,654 shares for $194,039.82, representing a +0.1% increase to its already substantial 16.82M share position. The blended purchase price of $8.96 sits below the current price of $9.35, and the stock has recovered +9.5% over the last 30 days despite being -35.6% from its 52-week high of $14.53. At this ticker, the insider has made 5 purchases since mid-June (all outcomes currently unmeasurable except one June 12 buy with a +12.5% 30-day return), suggesting continued accumulation during a period of relative price recovery. However, the company remains unprofitable with a -$23.5M net income in the latest quarter and -100.0% annual revenue growth, limiting the strength of any bullish signal from the transaction.

Director RA Capital Management adds 32,876 shares at $8.89 avg amid 5 rapid buys in 16 days; stock +48.8% in 90d.

RA Capital Management, LP filed Form 4 on 2026-06-25 reporting 2 separate purchases totaling 32,876 shares for $292,126.48 at a blended average price of $8.89 per share on 2026-06-25 and 2026-06-26. This transaction is the most recent of 5 consecutive buy transactions by the same director at ARTV executed over a 16-day window (2026-06-10 through 2026-06-25), with holdings expanding from 16.76M to 16.80M shares. Notably, ARTV trades at $9.58 currently, representing +48.8% gains over 90 days and +20.8% over 30 days, though the company is deeply unprofitable (latest quarter revenue of $251.0K, net loss of $-23.5M) and reported -100.0% annual revenue growth. The cross-ticker track record shows RA Capital's prior 20 open-market buys averaged +2.7% 30-day returns, but prior outcomes at ARTV are not yet measurable given the recent timing of all 5 purchases in this cluster.

RA Capital Management (10% owner) purchases 67,669 shares at avg $24.97 across 2 transactions, holding 6,444,637 shares post-transaction

RA Capital Management executed two separate purchases totaling 67,669 shares for $1,689,818.48 on 2026-06-15 and 2026-06-16, increasing its position by 1.1% to 6,444,637 shares. This builds on a consistent pattern: all 5 prior purchases at COAG were well-timed at the 90-day mark, with positive cumulative returns of +2.2% to +4.4%. The stock currently trades at $26.45, above the blended transaction price of $24.97 but -27.8% from its 52-week high of $36.61, and the company is operating at a net loss of $-22,687,000.00 with a market cap of $1,235,358,094.50. The consistent accumulation alongside a 100% track record at this specific ticker suggests methodical conviction, though the macro position (negative earnings, significant distance from highs) warrants close attention to whether the insider's prior success at COAG continues.

Director RA Capital Management buys 531,326 shares at $8.66 avg over 3 days despite stock down 8.9% in 30 days; stock still -38.7% from 52-week high.

RA Capital Management filed a Form 4 disclosing 3 separate purchases totaling 531,326 shares for $4,599,903.46 across a three-day window (June 12–16, 2026), with a blended average price of $8.66. The transactions increased the director's holding to 16,763,043 shares from 16,231,717 shares. Notably, this purchase occurred as the stock was trading -38.7% from its 52-week high of $14.53 and down 8.9% over the prior 30 days, though it has rebounded 53.6% over 90 days. The company is unprofitable with a quarterly revenue of $251,000 and full-year net income of -$23,516,000; annual revenue growth is -100.0%, indicating a material revenue decline. The director's prior purchase at ARTV (May 11, 2026) delivered a 90-day return of -30.6%, suggesting this ticker has not aligned with the director's cross-ticker buy success rate (93.33% 90-day win rate across all open-market holdings). The accumulation during a price decline and amid negative fundamentals warrants attention to whether this represents a conviction signal or portfolio mechanics.

RA Capital Management director acquired 21,188,750 shares ($423.8M) at $20.00 in PIPE placement at PBLS IPO.

RA Capital Management, LP, acting as director of Parabilis Medicines, completed 2 separate share purchases totaling 21,188,750 shares (21.19M shares) for $423,775,000.00 ($423.8M) at $20.00 per share on June 11, 2026. This transaction is a private placement (PIPE) allocation tied to PBLS's recent IPO, not a discretionary open-market purchase, so it reflects allocation participation rather than a conviction-driven buying signal. The company is trading at $25.01 as of June 15, 2026—four trading days after listing—representing modest outperformance versus the $20.00 subscription price. RA Capital's post-transaction non-derivative holdings of 2,648,278 shares reflect only a portion of the investor's total position; earlier preferred stock holdings are no longer reflected post-transaction, indicating conversion or redemption as part of the IPO transition.

RA Capital Management accumulates 1,027,722 shares in 3 purchases (June 9-11) at $7.44 average; stock down -24.7% in 30 days vs. -44.9% from 52-week high.

RA Capital Management, LP filed Form 4 disclosing 3 separate purchases totaling 1,027,722 shares for $7,650,148.29 at a blended average price of $7.44. The insider now holds 16,231,717 shares post-transaction, a +6.8% increase. At current price of $8.00, the stock is -24.7% over 30 days and -44.9% from its 52-week high of $14.53. The company reported latest quarterly revenue of $251,000.00, annual revenue growth of -100.0%, and net income of $-23,516,000.00, indicating a deeply unprofitable position with materially contracted revenue. This accumulation occurs while ARTV trades near mid-range of its 52-week spread and after the insider's prior buy on 2026-05-11 experienced a -35.6% loss over 30 days. The cross-ticker track record shows 93.33% accuracy on prior buys with +5.9% average 30-day returns, but the same-ticker history is unfavorable: 0 of 1 prior buys at ARTV were well-timed at the 90-day mark.

RA Capital Management (10% owner) purchased 4,798 shares at $24.96 avg across 2 transactions, bringing holdings to 6,376,968 shares

RA Capital Management executed 2 separate purchases totaling 4,798 shares for $119,776.18 on May 19–20, 2026, at an average price of $24.96. The transaction increased its stake from 6,372,170 shares to 6,376,968 shares, representing a net change of purchased 4,798 shares. Given Hemab's recent listing (14 trading days), the current price of $26.30 reflects early-stage market discovery. The modest incremental purchase and the minimal percentage increase in holdings suggest a measured approach rather than a concentrated accumulation event.

RA Capital Management bought 6,387 shares of COAG at $24.90, adding $159,036.30 to a 6.37M-share position in a recently listed stock.

RA Capital Management, LP, a 10% owner of Hemab Therapeutics Holdings, Inc. (COAG), purchased 6,387 shares at $24.90, bringing its total holding to 6,372,170 shares. The stock is in its early trading life with only 9 trading days since listing, and the current price of $28.37 sits above the transaction price, suggesting the position is in the money relative to this purchase. While the incremental dollar value of $159,036.30 is modest relative to the firm's existing 6.37M-share stake, the continued accumulation by a major 10% owner shortly after listing is a notable signal of sustained institutional commitment. Investors should monitor whether RA Capital continues to add to its position as the company establishes its post-listing trading history.

Ra Capital Management increases stake in ARTV by 75% with ~$75M open-market purchase; first buy at this company in 36 months.

Ra Capital Management, a board director and major shareholder, deployed approximately $75 million to acquire a substantial block of Artiva shares, expanding its indirect stake by more than 75 percent—the largest single acquisition in the fund's 36-month filing history at this company. The purchase occurred while the stock trades well below its 52-week high and follows a dramatic rally over the prior quarter, yet the company remains unprofitable with revenues declining sharply and significant annual net losses. Notably, this represents Ra Capital's first open-market purchase of ARTV shares on record, despite the fund's extensive trading activity across other holdings over the past three years—suggesting a deliberate shift toward this particular investment after a period of inactivity. The timing and scale of the buy are notable given the stock's weak fundamentals, though Ra Capital's prior open-market purchases across its broader portfolio have demonstrated a strong track record of capturing upside gains within 90 days.