Morgan Stanley (MS.N), which has spent three years throwing out bad apples from its fixed income trading portfolio, now wants to put the freed up money into businesses that bear healthier fruit. It is reinvesting capital previously held against unprofitable trades into areas like municipal bonds, credit and securitization, where it sees opportunities for boosting profit, senior executives at the bank said on Friday. This step represents a turning point in the bank’s efforts to shrink to the point where it can make money again in bond trading.