RA Capital Nexus Fund, LP

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.

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 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 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.

RA Capital Management purchased 7,111 shares of CLYM at $3.50 on 2026-01-05, growing position to 3,403,429 shares amid unprofitable fundamentals.

RA Capital Management acquired 7,111 shares at $3.50, a relatively small incremental addition to an already substantial 3.40M-share position, at a price 16.7% below the current market price of $4.20. The purchase follows two prior buys at the same ticker within days (2025-12-11 and 2025-12-12), suggesting repeated accumulation despite Climb Bio's unprofitable fundamentals—the company reported a net loss of $12.9M over its most recent full fiscal year. The stock has recovered sharply (+132.0% over 30 days, +122.2% over 90 days) from a 52-week low of $1.13, yet remains -14.8% from its 52-week high of $4.93. The insider's broader cross-ticker history shows 2 prior buys against 18 prior sells with a modest +4.5% average 30-day return following sales, which does not establish a strong pattern of timing acumen at this specific ticker.

Director RA Capital Management purchases 314,561 shares in 2 tranches at $2.18–$2.86; stock now at $3.81, up 100.5% in 30 days.

RA Capital Management, a Director, executed 2 separate purchases totaling 314,561 shares for $754,737.14 at prices ($2.18 and $2.86) well below the current price of $3.81, expanding holdings by 10.2% to 3,396,318 shares. The timing coincides with exceptional recent momentum: the stock has rallied 100.5% over the prior 30 days and 89.6% over 90 days, now sitting at its 52-week high. However, this purchase occurs against a backdrop of ongoing unprofitability ($-12,888,000.00 net income) and the insider's cross-ticker track record shows 20 prior sells with no offsetting buys recorded in the summarized history. The filing reflects a director's discretionary accumulation during a period of sharp stock appreciation, warrant deeper examination into whether this represents conviction in the company's turnaround or a specific investment thesis distinct from the broader momentum.

RA Capital Management sold 30,316 shares of SION for $1,200,703.87 across 12 transactions on Nov 20–21.

RA Capital Management, a director, executed 12 separate sales totaling 30,316 shares for $1,200,703.87 between November 20–21, reducing holdings by 16.0% from 189,349 to 159,033 shares. The sales occurred near the stock's 52-week high of $44.38, with a blended average price of $39.61, just ahead of the current price of $44.38. The company is unprofitable (net income of $-20,278,000.00) with a $2.0B market cap, and prior same-ticker trades at SION occurred immediately before this filing (November 19), suggesting continued portfolio management activity. The pattern of sustained high-volume selling at elevated valuations warrants investor attention to whether this reflects broader insider sentiment about near-term prospects.

RA Capital Management sells 136,351 shares (44.8% stake reduction) at blended $40.34 across 3 days; SION trading +19.3% (30d), -9.6% from 52-week high.

RA Capital Management sold 24 separate sales totaling 136,351 shares for $5,500,158.01 over a three-day window (Nov 17–19), reducing its holdings from 304,544 shares to 168,193 shares—a net reduction of 44.8% versus pre-transaction holdings. The blended average sale price of $40.34 sits 9.6% below the 52-week high of $42.50, yet 5.1% above the current price of $38.41; the stock has appreciated 19.3% over the past 30 days and 61.8% over the past 90 days. At the cross-ticker level, RA Capital's track record shows 17 prior sells with an average 90-day return of -15.6%, though at this specific ticker (SION), five prior sales occurred on Oct 24 and Oct 28, with outcomes still not yet measurable. The company itself is unprofitable (net income of -$20,278,000.00) and valued at $1,714,191,747.08, providing financial context for an investor evaluating the significance of a major director's exit.

RA Capital sold 373.6K shares (64.1% of holdings) at $39.50–$39.58 for $14.8M in 8 transactions

RA Capital Management, L.P. (Director) executed 8 separate sales totaling 373,610 shares for $14,762,603.80 across October 24–28, 2025, reducing its stake from 583,001 shares to 209,391 shares. The blended average sale price of $39.51 falls close to the current price of $39.45 and near the 52-week high of $42.50, positioning the sells near recent peak valuation. The stock's 30-day gain of +36.3% and 90-day gain of +122.2% show sharp recent appreciation preceding these sales. Sionna Therapeutics is unprofitable (net income of $-18,068,000.00) with a $1.7B market cap. The scale of this disposition—divesting nearly two-thirds of the director's position—marks a material reduction in insider ownership, and the concentration of activity over a four-day window suggests a coordinated exit rather than a gradual adjustment. This sale pattern and price timing warrant scrutiny given the stock's recent volatility and the director's remaining 209.4K share holding.

RA Capital Management sold 117,050 shares at $29.34 avg for $3.4M on 2025-10-20–21, reducing stake by 7.7% amid -50.4% decline from 52-week high.

RA Capital Management, a director of Vor Biopharma, executed 5 separate sales totaling 117,050 shares for $3,433,992.06 at a blended average price of $29.34, reducing holdings from 1,518,276 to 1,401,226 shares. The timing is notable: the sales occurred at prices ($29.63–$30.12 on 2025-10-20, and $28.11 on 2025-10-21) that stand well above the current price of $26.50, and within weeks after the company's 52-week high of $53.40, from which the stock has fallen 50.4%. The company is unprofitable with a net loss of $1,573,669,000, trading on the basis of biotech pipeline potential rather than current earnings. While the director retained 1.40M shares post-sale, the execution of multiple sales within a two-day window at elevated relative valuations warrants investor attention to whether this reflects internal reassessment of near-term outlook or valuation inflection.