Editor's note: The following are questions received from listeners of "RealMoney Radio." To send Cramer a question about topics from his radio show, click here. Listen to Cramer's latest radio show by clicking here. Jim, what do you think of William O'Neil's rule of never averaging down on a stock? -- Joe from Ohio James J. Cramer: I believe that when trading, which uses a short-term time horizon, it is never wise to add to a losing position. But when investing for the medium- to long-term, I often will add to stocks when they are down if the fundamentals are still strong. Jim, what's your thinking on JP Morgan Chase (JPM)? -- Joseph from Canada James J. Cramer: I believe JP Morgan Chase works here. Jamie Dimon will be taking the reigns very soon, and I believe he was key to Sandy Weill's success at Citigroup ( C). I believe the 4% dividend yield is safe and that Dimon will hit the ground running, cutting costs and getting all the company's businesses into tip-top shape. Want more Cramer? Check out Jim's rules and commandments for investing from his latest book by clicking here.