Hi doma,
The value of all paper reduces relatively-speaking when the CBs create new money. So when the CB does this in a period of deflation such as the one we are experiencing, this makes it less comfortable to sit on it. In turn, this makes investment relatively appealing.
To keep up with the real value of money, you need to put it in a security or bond that offers interest. And then you need to have it compound. You can do this by investing in Treasuries, say, although what the exact relationship is between compounded Treasuries and inflation I don't have in my hands.
In the longer run, the paper used to make stock certificates has tended to outperform the paper used to make bonds and the paper used to make cash.