question: What is the profession of Mason's ex-fiancee?
context: In New York City, high-strung equity trader Joy Ellis McNally is dumped by her fiancé at a surprise birthday party she throws for him. At the same time, easy-going carpenter Jack Fuller is fired from his job by his father, Jack, Sr. Both become emotionally distraught and, with best friends Toni "Tipper", a bartender, and Jeff "Hater", a lawyer, take a debauched trip to Las Vegas.
  Joy and Jack meet by chance when they are given the same hotel room because of a computer error. After clearing up the misunderstanding and receiving upgraded rooms and coupons to various clubs, they party and drink together and end up getting married. The next morning, they realize it was a mistake and decide to divorce.
  Before they do so, Jack uses a quarter Joy gives him in a slot machine. He hits a three million dollar jackpot and Joy reminds Jack that they are married and hence, she is entitled to half of the money. The couple return to New York, where they attempt to divorce. The judge declares that the couple cannot divorce until they attempt to co-exist for six months, while attending weekly sessions with Dr. Twitchell, a marriage counselor. If they work at the marriage but still want to divorce after six months, each will be permitted to keep half the winnings. If either party does not cooperate, the money will be tied up in litigation by the judge.
  The newlyweds devise more and more cunning schemes to undermine each other, such as Jack telling Joy that their counseling session is canceled to prove she's not committed, and Joy inviting girls to their apartment to try to get Jack to cheat on her, throwing a party where Jack's friend Dave shows up. Jack gives Joy's ex-fiancé, Mason, her engagement ring back without Joy knowing. At Joy's job retreat, Jack and Joy find themselves developing an unexpected attraction to one another, and they soon realize that being with each other has brought out the best in both of them.
answers.text: equity trader