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William D. Mccombe

CTKB
CHIEF FINANCIAL OFFICER · CYTEK BIOSCIENCES, INC. · CIK 0001878824
FILING MIX · LIFETIME45%/55%
BUYS
18
SELLS
22
TOTAL VALUE
$272.0K
COMPANIES
1
ACTIVE SINCE
May 2024
HOLDINGS NOW
101,007
AVG SELL PX
$3.80
TRADE KIND
SHOWING 40 / 40
Trades · vs SPY
Loading price series…
Performance · forward returns vs SPY
1 backtested trades · 8 horizons · 1 pending
Forward-return performance of every backtestable P/S trade by William D. Mccombe, measured at 8 horizons from 7 days to 2 years. Deduped per economic event so co-filings count once. Excess return = trade return minus SPY return over the same window.
HORIZONTRADESWIN RATEINSIDER RETURNSPY RETURNMEAN EXCESSMEDIAN EXCESST-STAT
7d1+100.00%+25.80%+1.18%+24.62%+24.62%—
14d1+100.00%+16.61%+1.68%+14.93%+14.93%—
30d1+100.00%+27.56%+4.68%+22.88%+22.88%—
60d1+100.00%+28.62%+4.89%+23.73%+23.73%—
90d1+100.00%+46.29%+8.83%+37.46%+37.46%—
180d1+100.00%+99.65%+15.30%+84.35%+84.35%—
1y1+100.00%+48.06%————
2y1(1 pending)——————
How to read this: Insider Returnis the average raw return of the filer's trades over the horizon. SPY Return is what SPY did over those same windows — reference only, not a comparison. The headline alpha number is Mean Excess = Insider − SPY; green means the filer beat SPY, red means they trailed it. Win rate is the share of individual trades where the filer beat SPY. T-statvalues above 2 mean the alpha is unlikely to be chance given the sample size. "Pending" counts trades where the horizon hasn't elapsed yet; their stats are not included in the row average.
Holdings over time
CTKB · 101,007 shares · as of May 18, 2026
082,721165,441248,162330,88220252026SHARES HELD
Trading cadence · quarterly flow
BUY ● SELL ●
2024
2024
2024
2025
2025
2025
2025
2026
2026
FLOW · 18 buys / 22 sellsCOVERAGE · 9 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
2,268$3.55$8.1K98,739May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
10,699——246,091May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
3,839$3.55$13.6K111,177May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
8,700——107,439May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
8,700——147,913May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
10,699——115,016May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
6,320——50,569May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
3,122$3.55$11.1K104,317May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
6,320——101,007May 18, 2026May 20, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
6,320——87,034Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
17,401——156,613Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
136,205——136,205Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
7,145$4.23$30.2K94,687Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
6,320——56,889Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
256,790——256,790Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
17,401——101,832Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
2,603$4.23$11.0K84,431Mar 10, 2026Mar 12, 2026 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
6,320——73,891Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
6,320——63,209Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
13,051——84,910Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
13,051——174,014Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
4,196$5.53$23.2K80,714Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
2,032$5.53$11.2K71,859Nov 18, 2025Nov 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
5,084$4.06$20.6K67,571Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
2,462$4.06$10.0K59,604Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
6,320——62,066Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
13,051——187,065Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
13,051——72,655Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
6,320——69,529Aug 18, 2025Aug 20, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
35,000$2.78$97.3K55,746Jun 2, 2025Jun 3, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
25,283——75,849May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
3,389$2.69$9.1K20,746May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
8,700——24,135May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASE
Chief Financial Officer
25,283——25,283May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
8,700——200,116May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
SALE
Chief Financial Officer
9,848$2.69$26.5K15,435May 19, 2025May 21, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
208,816——208,816Mar 4, 2025Mar 6, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
330,882——330,882Mar 4, 2025Mar 6, 2025 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
101,132——101,132May 13, 2024May 15, 2024 ↗View →
CTKB
CYTEK BIOSCIENCES, INC.
PURCHASEGRANT
Stock grant
150,602——150,602May 13, 2024May 15, 2024 ↗View →
Other insiders · CTKB
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About this filer
CIK 0001878824
ROLE
Chief Financial Officer
PRIMARY
CTKB
COMPANIES
1
ACTIVE SINCE
May 2024
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