This stock is overvalued - non regarding what short interest is existing.
The management is spending millions of US$ each quarter. Last year CLDX has burned more than 40 million US$ of assets.
Now they will burn much more after they bought CRGN.
You should take a look at the biggest stockholders of CLDX - Medarex and Lorantis. The lock uperiod has been finished last march and now they are able to sell their shares - millions of shares and cash in the money.
You should be careful - propably it is dead money which you are investing here...