People often compare the speculative bubble of Tulip Mania hundreds of years ago with that of Bitcoin. Gold also tends to have speculative bubbles when stock markets crash.
I've been pondering the Tulip thing and the whole concept seems flawed to me for one simple reason:
A Tulip bulb could cost many thousands of dollars, but wouldn't most people have planted it to gain more tulip bulbs with the aim of selling them, ultimately flooding the market and inevitably driving prices down again?
As far as I can remember, the tulip mania thing was actually caused by a variety of tulip which developed a virus which
affected the colour of the petal, it was quite unique and highly sought after, but was just a flower.
Bitcoin on the other hand has a real world use.
Here is an interesting thread, why is Bitcoin valuable -
https://bitcointalksearch.org/topic/m.28764408and a quote from that thread
What is Censorship Resistance and Why Would It Make Bitcoin Valuable?
Cash being an exception, payments usually run through central payment processors such as PayPal, VISA or your local bank.
This works fine, until it doesn't. PayPal is known for more or less randomly freezing merchant accounts, essentially locking them out of their money. Credit Card providers such as VISA have blocked payments in the past -- look up what happened to Wikileaks as an example. Local banks can go bust during bank runs and shut down accounts if they find your transaction suspicious -- whatever that may mean.
Nothing of the above apply to Bitcoin. Bitcoin takes the power and responsibility away from third parties and puts it back in the hand of the actual owner. Hence it being censorship resistance, an attribute that has been rather unusual for a currency -- until now.