Washington Irving's "The Devil and Tom Walker" tells of the age old story of selling one's soul to the Devil. Typically, one desires something so much that he or she is willing to give up his or her soul. In the case of Tom Walker, he desires wealth so fervently that he makes a deal with the Devil.
Both Tom and his wife are misers (a person who hoards money and spends as little as possible). Therefore, both of them possess the "bad trait" of hoarding. Both Tom and his wife fight constantly about money; these fights turn physical at times. One could state this is another "bad trait" the couple possesses. Finally, each is willing to cheat one another. Any money which is brought into the home is susceptible to being stolen by the other. Both are willing to lie and steal from one another.
Essentially, neither Tom Walker nor his wife possess good traits. While Tom does show one moment of goodness (when he refuses to be a slave trader), he does become a usurer (one who lends money at a high rate of interest).