KEY POINTS
  • "Mad Money" host Jim Cramer shared the two most important investing rules he has learned after nearly 40 years in the business.
  • Rule No. 1: Bulls make money, bears make money, and pigs get slaughtered.
  • Rule No. 2: Don't be greedy.

CNBC's Jim Cramer knows that he constantly repeats the same old investing rules, but it's because rules mean discipline, and discipline always trumps conviction.

"One thing I've learned in my investing career: no matter how much you might believe in something, you violate the rules of the road at your own peril," the "Mad Money" host said.