If all MIR retail investors are excited about a forthcoming news after being loyal to a company for a long time, they are not going to sell their shares days before the "Big" news.  If there is a seller, then that seller must have some insider information that is giving him/her reason(s) to sell.

Then again, sometimes people can be tricked into thinking that they have an inside knowledge only to realize that they were not "inside" enough...or trust somebody who was mislead/tricked him/her self...

Remember how William Wallace was captured in Braveheart in the end?