Look at companies where stocks dip or rise a few days to the day before earnings are announced. How does this happen if they don’t know something the general pu

Look at companies where stocks dip or rise a few days to the day before earnings are announced. How does this happen if they don’t know something the general public or most other investment firms don’t know? Agreed that the people getting caught are dumb. Especially making trades about your ex employer when you’ve already started an insider trading ring.