[jakobegger]

Why not just leave it at the bank?

It's always nice to have a bit of money on the side for unexpected expenses (eg. car breaks down) or if you should find yourself without a job for a few months, or if you need a down payment to buy an appartement.

If your money is tied up in investements, it's just going to be a hassle to get to your money, and it's going to cost a lot in fees if you need it sooner than later.