 Given the famous “money pump argument,” developed by Donald Davidson, J. McKinsey, and Patrick Suppes (1955), it is clear that intransitive preferences can be problematic. Like Dutch book arguments regarding betting, in which the rationality of an agent is put into question because the agent is susceptible to having a book made against her (i.e., to accepting a series of bets which are such that she is bound to lose more than she can gain), the money-pump argument is concerned with agents who are vulnerable to making a combination of choices that lead to a sure loss. According to the money-pump argument, intransitive preferences are irrational because they can prompt an agent to accept a series of trade offers that leaves the agent with the same option he began with, but with less money. Here is a case of the relevant sort. Suppose that Alex has the following intransitive preferences: he prefers owning a computer of type A to owning a computer of type B, owning a computer of type B to owning a computer of type C, and owning a computer of type C to owning a computer of type A. Suppose also that Alex owns a computer of type C and a hundred dollars in spending money. Suppose finally that, given his preferences between different computer types, Alex prefers (i) owning a computer of type B and one less dollar of spending money over owning a computer of type C, (ii) owning a computer of type A and one less dollar of spending money over owning a computer of type B, and (iii) owning a computer of type C and one less dollar of spending money over owning a computer of type A. Then a series of unanticipated trade opportunities can spell trouble for Alex. In particular, given the opportunity to trade his current (type C) computer and a dollar for a computer of type B, Alex’s preferences will prompt him to make the trade. Given the further opportunity to trade his current (type B) computer and a dollar for a computer of type A, Alex’s preferences will prompt him to trade again. And given the opportunity to trade his current (type A) computer and a dollar for a computer of type C, Alex’s preferences will prompt him to make a third trade. But this series of trades leaves Alex with the type of computer he started off with and only 97 dollars. And, given that unexpected trading opportunities may keep popping up, Alex’s situation may continue to deteriorate. Even though he values his spending money, his preferences make him susceptible to being used as a ‘money pump.’ Moreover, interesting variations on the basic money pump argument show that an agent with intransitive preferences like those just considered is susceptible to being money-pumped even if he shows foresight and correctly anticipates his upcoming trading opportunities. See, for example, Rabinowicz 2000 and Dougherty 2014.