<p>Especially trading, at least with sales maybe you could still use the same skill to sale dog food. Traders are not trained to be managers (people), marketers, relationship managers (clients). They don’t even know how to manage a portfolio because they often only know one product. With younger traders, a firm could afford to move them to different desks if they should decide to get out of a line of business. But with seasoned traders it would be more costly - look at all the MBS traders on the street. Traders work under a lot of pressure, that’s also why they like younger traders. If you are very disciplined, you could save your money and do something else after 35 or 40 (the question is what). This is just my opinion.</p>