If an insider did know, before the public, that an

If an insider did know, before the public, that an approval or EUA or any "great" news for example was going to be announced, and then bought 195,500 shares, that could cause him a big legal problem. Thus, his purchase tells us there is probably not an some "great" news tomorrow, although there may be "good" news, or several reports of "good news" ????