Ann: New Health Sensor Patent Applications Covering Gaming, Computer Devices, and Other Electronic Hardware, page-102

Personally I don't think its only trading and the general observation of @stormer is correct .... somebody is  offloading since about 3 month and my guess it is Paul Cozzi the second biggest shareholder after Coops and Niall shares in C2 ventures. Mister Paul Cozzi is a wealthy investor and trader, who holds in several companies Top 20 positions. Since 3 month  Paul Cozzie liquidated many shares in several companies partly  out of whatever personal reasons. I don't think its about the progress or performance of CDX, rather more about that he already sits on a healthy 3 bagger.
Here is an article from September 2020...
https://au.finance.yahoo.com/news/trade-alert-cardiex-limited-asx-215352259.html
OK...its only a guessing game, but the answer to this question who the big seller is will be answered in the next annual report which should be due by end of this month. I asked the company about an updated top 20 statement...but no answer so far. I think without this relentless selling CDX would have punched through the 10 cent mark and hold the double digits....CDX is kind of spring loaded...
and when it runs, it will run hard...IMO