kd26gioi

That's what I meant. Obviously, most traders are people who wanted to work in finance/asset management/investment banking/etc. The random part is that they ended up in trading rather than another field in finance. If you are a bright young college graduate looking to work on Wall Street, you don't just apply for trading jobs - you apply broadly to many bank jobs and accept the best offer that you get.

Also, obviously you don't make money on each day. However, everyone has a reasonable boundary for acceptable daily losses. If you lose $100,000 today, maybe that's ok. But if something happens and you lose $10 million today, maybe you will not have a job tomorrow.