Well, I understand somehow people believe the money as something "stable". But just take a look at the dollar on the past 3 years: it has been dancing as a newbie ice-skater.
There´s no such a thing as "stable" on economics. And I´m afraid there are not going to be. BTC, as a whole new system of "money", is going to be "dancing" for years and, for sure, it will never become something static (as the dollar, euro, Yuan, &.co have never been).
That's right. It's not meant to stay stable at one price. It will keep jumping up and down. As you stated, not only BTC, fiat currencies too keep going up and down. Whole point is to leverage the benefits of the moves!