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EdgarHawk

Casdin Partners Master Fund, LP

Director

Director 10% Owner

Latest: Insider selling · May 2026

21 filings analyzed · 2 companies · Latest 2026-05-21

Companies

Company Buys Sells Direction
BIOLIFE SOLUTIONS INC BLFS 0 7 Net selling
STANDARD BIOTOOLS INC. LAB 40 0 Net buying

Activity

May 2026
2026-05-21 BIOLIFE SOLUTIONS INC BLFS
high
Sell
1,200,000 shares
$28,125,000
Significance 7/10

Casdin Partners (10% owner) sells 1,200,000 shares across 3 trades for $28,125,000.00; holdings drop to 4.76M shares (-20.1%).

Casdin Partners Master Fund, LP, a 10% stakeholder, executed 3 separate sales totaling 1,200,000 shares for $28,125,000.00 at a blended average price of $23.44 over three consecutive trading days (May 19–21, 2026), reducing holdings from 5.96M to 4.76M shares. The insider's prior sale at BLFS on 2025-10-15 showed a 90d return of -16.3%, demonstrating a 100.00% well-timed rate at this ticker. The company remains unprofitable on a full-year basis despite quarterly revenue of $27,500,000.00 and annual revenue growth of +17.0%, creating a disconnect between top-line momentum and bottom-line profitability that warrants investor attention. At the current price of $24.74, the stock is +10.6% over 30 days and -16.5% from its 52-week high, placing this sale within a period of near-term strength but medium-term weakness.

December 2025
high
Buy
350,000 shares
$502,570
Significance 6/10

Casdin Partners Master Fund, L.P. (Director) purchased 350,000 shares over 3 days (Dec 2-4) at blended avg $1.44, building position to 72.10M shares.

Casdin Partners executed 3 separate purchases totaling 350,000 shares for $502,570.00 across December 2–4, 2025, at prices ranging from $1.42 to $1.45, during a period when LAB stock has rebounded +21.0% over 30 days and +10.8% over 90 days from a 52-week low of $0.92. The transaction occurred in the context of a company with $19.6M quarterly revenue and negative net income of $-34.7M, though annual growth has accelerated +64.0%. Casdin Partners' cross-ticker track record shows strong outcomes (83.33% 90-day win rate, +8.0% avg 90d return on 19 prior buys), but those transactions across other tickers do not yet indicate success at LAB—the 5 prior same-ticker purchases in late November have outcomes not yet measurable. This incremental accumulation (+0.5% vs pre-transaction holdings) suggests continued positioning in LAB after a rapid price recovery, though the unprofitable operating performance and recent timing—well into a 30-day rally—warrant monitoring of near-term fundamentals and execution.

November 2025
high
Buy
7,700,000 shares
$10,053,280
Significance 7/10

Casdin Partners Master Fund purchases 7,700,000 shares at blended $1.31, raising stake to 71.75M shares in unprofitable LAB

Casdin Partners Master Fund, as a director of Standard Biotools, executed 2 separate purchases totaling 7,700,000 shares for $10,053,280.00 on 2025-11-24 and 2025-11-25, at prices of $1.43 and $1.30 respectively. This acquisition increased the insider's holdings by 12.0% to 71,750,000 shares. The transaction occurs within a context of elevated recent trading activity at LAB—the SAME-TICKER HISTORY shows 5 prior buys in the preceding week (2025-11-14 through 2025-11-20)—suggesting sustained accumulation by this insider. However, the company posted a negative net income of $-34,687,000.00 on quarterly revenue of $19,552,000.00 and remains unprofitable on a full-year basis, despite 64.0% annual revenue growth. The current stock price of $1.43 is 35.3% below the 52-week high, positioning these purchases in a depressed price zone relative to historical range. Investors should focus on whether this concentration of director purchases reflects conviction in a distressed but growing technology platform, or is driven by other factors external to near-term performance signals.

medium
Buy
925,000 shares
$1,126,775
Significance 6/10

Casdin Partners purchased 925,000 shares across 3 trades (Nov 13–17) at blended $1.22, adding to 62.98M-share position in unprofitable LAB.

Casdin Partners Master Fund, L.P. filed 3 separate purchases totaling 925,000 shares for $1,126,775.00 between November 13–17, 2025, at prices ranging from $1.20 to $1.24 and a blended average of $1.22. The transactions increased the director's holdings by 1.5% to 62,975,000 shares. The current price of $1.21 sits 45.2% below the 52-week high of $2.21 and has declined 4.7% over both the 30- and 90-day periods, placing the purchase in a downtrend. At the same ticker, Casdin has executed 5 prior trades in rapid succession (September 9 through November 12), all purchases, with the earliest showing a modest +5.5% 30-day return but outcomes beyond 30 days not yet measurable. Cross-ticker, Casdin's historical track record shows 16 prior buys with an average 30-day return of +2.0% but an average 90-day return of -10.9% and a 0.00% win rate at the 90-day mark, indicating a pattern of purchases that subsequently underperform. Standard Biotools remains unprofitable ($-34.7M net income on $19.6M quarterly revenue) despite 64% annual revenue growth, a structural condition that may constrain upside and heighten downside risk in a declining market.

high
Buy
1,175,000 shares
$1,379,318
Significance 7/10

Casdin Partners bought 1,175,000 LAB shares over 4 days (Nov 7–12) for $1.4M at blended avg $1.17, expanding stake to 62.05M shares as stock trades 47.1% below 52-week high.

Casdin Partners, a director and substantial shareholder of Standard Biotools, executed 4 separate purchases totaling 1,175,000 (1.18M shares) for $1,379,317.50 ($1.4M) between November 7–12, 2025, at prices ranging from $1.12 to $1.20, slightly below the current market price of $1.18. The blended average price of $1.17 represents purchases into a stock trading 47.1% below its 52-week high and down 8.5% over the prior 30 days. Holdings expanded by 1.9% to 62.05M shares post-transaction. At the same ticker, Casdin's prior 5 buys (August 25–September 9) all showed positive 30-day returns (+4.9% to +5.9%), though none has yet completed a 90-day measurement window. The company remains unprofitable (net income $-34.7M in the most recent full fiscal year) despite annual revenue growth of 64.0%, and current market capitalization stands at $453.8M. This sustained accumulation into a distressed valuation warrants monitoring for whether the outsized revenue growth trajectory supports a recovery from depressed price levels.

October 2025
2025-10-17 BIOLIFE SOLUTIONS INC BLFS
high
Sell
750,000 shares
$21,410,325
Significance 6/10

Casdin Partners (10% owner) sold 750,000 shares of BLFS at $28.55 on 2025-10-15; now holds 5.96M shares.

Casdin Partners, a 10% shareholder, sold 750,000 shares (-11.2% of prior holdings) near the 52-week high ($28.55 vs $28.75 peak). The company faces significant fundamental headwinds: annual revenue declined 42.6% and net income was negative $15,838,000.00 on quarterly revenue of $25,421,000.00. At the same ticker, Casdin's prior three trades show a mixed pattern: two recent sells in August (30d returns +4.6% and +17.2%) and a June sell that returned -4.5% over 30 days but +10.2% over 90 days, with zero of one measurable sells well-timed at the 90-day mark. The sale occurs after a +31.2% 90-day rally, reducing concentrated exposure in a fundamentally challenged company while the stock remains near recent peaks.

September 2025
medium
Buy
100,000 shares
$128,920
Significance 4/10

Casdin Partners bought 100,000 shares of Standard Biotools at $1.29; stock down -41.2% from 52-week high.

Casdin Partners increased its stake in Standard Biotools by 100,000 shares (100.0K shares) on 2025-09-09 at $1.29, part of a series of five purchases since 2025-08-22. The stock trades at $1.33, down -41.2% from its 52-week high of $2.26, though up +26.7% over the past 90 days. Standard Biotools reported revenue of $21,762,000.00 with net income of $-33,459,000.00 in its latest quarter and remains unprofitable on an annual basis, despite showing +64.0% annual revenue growth. The insider's own cross-ticker track record shows a 90-day win rate of just 11.11% on buys, with prior purchases averaging -13.4% 90-day returns. No measurable outcome exists yet for the five recent purchases at this ticker.

medium
Buy
500,000 shares
$635,750
Significance 5/10

Casdin Partners bought 500,000 shares (500.0K) at avg $1.27, raising stake to 60.78M; stock up 22.6% in 90d but deeply unprofitable.

Casdin Partners Master Fund made two separate purchases totaling 500,000 shares for $635,750.00 on consecutive days (2025-09-03 and 2025-09-04) at an average blended price of $1.27, increasing holdings from 60.28M to 60.78M shares. The stock has appreciated 22.6% over the prior 90 days and trades at $1.30, well above the transaction prices, suggesting the purchases were made into a rallying period. However, Standard BioTools remains deeply unprofitable with a net loss of $33,459,000.00 against quarterly revenue of $21,762,000.00, despite 64.0% annual revenue growth. Casdin's five prior purchases at this ticker (all within the prior two weeks in August 2025) signal sustained accumulation, but outcomes are not yet measurable. The cross-ticker track record shows a 27.27% win rate on buys at the 90-day horizon—a notably poor success rate—suggesting caution about relying on historical timing patterns to predict this position's performance.

August 2025
high
Buy
525,000 shares
$658,798
Significance 6/10

Director fund purchased 525,000 shares at $1.25 avg (Aug 22–26) amid -42.9% drawdown from 52-week high

Casdin Partners Master Fund, L.P., a director at Standard Biotools, executed 3 separate purchases totaling 525,000 shares for $658,797.50 between August 22–26, 2025, at prices ranging from $1.24 to $1.26. The current price of $1.29 sits -42.9% below the 52-week high of $2.26 and has declined -7.9% over the past 30 days, suggesting the company faces near-term headwinds. At the same-ticker level, Casdin's prior two measurable outcomes showed mixed results: a +7.0% 30-day return on a February 2025 buy but a -25.9% 90-day return on an August 2024 buy, indicating inconsistent timing on prior LAB purchases. The company reported a net loss of $33,459,000.00 on quarterly revenue of $21,762,000.00, though full-year revenue growth reached +64.0%, showing execution challenges in profitability despite top-line expansion. The concentration of three buys in consecutive trading days during a depressed price window merits investor scrutiny of whether the fundamental picture has stabilized or whether the timing reflects exogenous factors rather than conviction tied to operational recovery.

2025-08-21 BIOLIFE SOLUTIONS INC BLFS
medium
Sell
500,000 shares
$12,200,000
Significance 5/10

Casdin Partners (10% owner) sells 500.0K BLFS shares at $24.40; stock now $25.08 amid -42.6% annual revenue decline.

Casdin Partners sold 500,000 shares of BIOLIFE SOLUTIONS at $24.40 on 2025-08-15, reducing holdings by -6.9% from 7,207,165 to 6,707,165 shares. This is the fund's second sale at BLFS in five days (prior sell on 2025-08-11), suggesting deliberate liquidation activity near the current price of $25.08, which is -12.0% from the 52-week high. The company faces significant operational headwinds: revenue declined -42.6% year-over-year and the business is unprofitable with net income of $-15,838,000 on quarterly revenue of $25,421,000. Casdin's cross-ticker track record shows only 2 prior sells with an average 30-day return of -4.5%, a limited sample; the prior BLFS sale on 2025-06-10 posted a -4.5% 30-day return, though longer-term outcomes remain unmeasurable. The timing and concentration of recent liquidation against deteriorating financial fundamentals are relevant context for investors monitoring this position.

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