Michael was a trainee with Salomon Brothers investment bank in 1985 and then worked for them as a bond salesman until after the 1987 crash.
The book has three parts, largely unrelated and written in different styles.
The first part in about Michael’s studies, why he wanted to work on Wall Street; how he got the job at Salomon Brothers and his few months of induction course. It is written in first person and not very interesting, except for the atmosphere it introduces.
The second part is a story about how mortgages on houses were packaged to be sold as bonds almost single-handedly by a guy called Ranieri – who apparently raised himself through the ranks from working in the mailroom to developing and selling a whole new product on the market: the mortgage bonds. This chapter is not written from Lewis’ personal experience but more like a wall street journal report and features quotes drawn from interviews with various people. This bit is worth reading as it explains how the mortgage bonds came about and why are they dangerous investments in certain market conditions.
Finally, Michael starts working as a bonds salesman in the London office and gets back to telling the story from his own perspective. He goes through the hostile almost-takeover of Salomon Brothers but survives his job. He also tells the story of the 1987 market crash (which is another bit of interesting read).
Generally, the book describes the “culture” of Wall Street at the time. It is totally unflattering and portrays Wall Street traders and salesmen as unscrupulous people who took advantage of others’ ignorance. They have a lust for money and contempt for everybody else who doesn’t make as much as they do (which is why Michael wanted the job in the first place!).
The game is not properly described in the book, but here is a web site that details it!