<<Profit taking. I sold a few thousand shares of DNDN this morning and put the money into other stocks - mostly biotechs.>
The question is whether the new buyers of DNDN are more or less likely to be funding their DNDN purchases with sales of other biotech than the DNDN sellers are to be redeploying the proceeds of the sale in other biotech.
But someone bought the shares you just sold! The buyer of those shares may have sold some other biotech (or refrained from buying one) in order to fund the DNDN purchase.
Bottom line: DNDN’s news does not suggest there will be net money flowing from DNDN to other biotechs, as y3maxx implied.