Your question is best answered with ref to my post 11263, para 3, & para 4 last sentence.
Peter Snodgrass
A highly intelligent near ninety year old racing driver into stocks and shares, well I never did. Respect.
Edit. Your point about "already have passed the approval stage" (CJD/BSE) and thus saving time when a government announcement comes could be valid.
I spent quite a long time during my 4 day break from work reading up on Aventis, I started with the 100 odd page 2001 accounts pdf file; most most interesting!