Cytek Biosciences (CTKB)

As of 30 September 2026, short interest in CTKB is 5,215,595 shares, up 284,567 shares over the last month. Over the last 48 readings it ranged from 3,173,072 shares (31 January 2025) to 8,096,762 shares (15 April 2026). At the reported average volume of 1.7M shares a day that is 3.1 days to cover.

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As of 12 October 2026, the short share of CTKB volume is 39.6%, up 9.2 points over the last five sessions. Over the last 30 readings it ranged from 15.0% (9 October 2026) to 67.2% (14 September 2026). The latest reading is in line with the 30-session average of 37.7%, on 339K shares reported.

As of 10 September 2026, the fails-to-deliver balance in CTKB is 5,910 shares, up 5,862 shares over the last settlement date. Over the last 30 readings it ranged from 1 share (12 March 2026) to 9,100 shares (1 April 2026).

No open-market insider trades were reported for CTKB in the last 90 days. The most recent filings are listed below. Latest filing: Yan Ming (CHIEF TECHNOLOGY OFFICER) on 2026-08-18.

Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.

1 Form 144 notice on file for CTKB worth $147K at the prices reported; 1 in the last 90 days worth $147K. Latest: PHILIPPE BUSQUE filed on 2026-09-02 to sell 31,666 shares ($147K) from 2026-09-02.

9 holders report 5% or more of CTKB in their latest filing, all on Schedule 13G (passive). The largest reported stake is Millennium Management LLC at 7.2% of the class (9,338,010 shares), filed 2026-08-06 for an event on 2026-06-30.

7 of the 30 tracked managers held CTKB at their latest 13F, $56.7M in total at quarter-end prices. Millennium Management is the largest at $41.4M (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 5 added shares and 2 cut.

Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.

In Q2 FY 2026 (quarter ended 2026-06-30) Cytek Biosciences reported revenue of $48.1M, up 5.6% from the same quarter a year earlier, and net loss of $12.2M. In FY 2025 it generated -$4.7M of operating cash flow and spent $15.1M on buybacks.

Quarterly, last 8 quarters

Fiscal years, with buybacks and dividends

Quarters are the three-month figures the company reports; a fourth quarter marked derived is the fiscal year less the three reported quarters, since companies report it only inside the 10-K. Fiscal years are the annual figures. Buybacks are the cash the company paid to repurchase its common stock in the year, not the amount authorized. Balance sheet lines are as of 2026-06-30; shares outstanding as of 2026-07-31 from the cover page.