I really wonder what your definition of stable is?

I would say having a maximum price change of a few percentage per day and the same per week. On a monthly basis the changes should have a maximum of like 10%. Of course you can always have a month with a higher percentage. But not every month and for every crypto.

So to my opinion the crypto market is not stable. And due to the mechanics of how crypto works now, there is a very big chance it will never become stable.