You can't really call a bank a bubble. Is Google a bubble? Google and banks are business. Their stocks are rising because of their sales and real profits. Sure investors drive their stocks up, but even without investors, their stocks wouldn't drop as much. In other words, they wouldn't die without their investors/stockholders.
But crypto-currencies? It is 100% investor driven. It is worth what it is worth today because of consumers. Unless they plan to buy it and keep it forever, which I doubt, it will one day collapse. Sooner than later. I just don't see any longevity in bitcoin. But hey, I could be wrong. Maybe it will outlive Google. Maybe bitcoin will be the currency of Mars. Maybe Crypto-currency is the future and cash will go obsolete. *shrug* But I doubt it.