Of course, but the traders are taking risks in the sense that they can get fired for losing money. Programmers generally won't. They have a lower-risk, more secure job.

If it turns out that the reason for losing money is the faulty code from a developer, he can lose his job. So I don't see where the security is.

That's different. The security is: if a programmer implements the code correctly, but the market turns against the strategy and the strategy loses money, the programmer generally won't lose his job.