Although a stockbroker need not have done anything either illegal or im moral if a client's account suffers a loss, problems arise in cases of unauthorized trading, cases in which investments are unsuitable, i.e., securities selected do not meet the investor's objectives, and cases of churning the investor's account. In this essay we focus on situations in which no unauthorized trading occurred and in which securities selected were suit able to the customer's objectives; our interest is solely in churning. We shall examine two current definitions of "churning" and two companion accounts of the criteria necessary to establish that churning occurred. We favor one definition and its attendant criteria, and shall argue for them and against the other definition with its attendant criteria.