Bitcoin / Bitcoins / Crypto Currency

That's not gambling at all - That's exploiting greed and ignorance.

There are elements of gambling involved - CDS / CDOs, for example, are insurance against a revenue stream going tits up - and if you don't buy the underlying instrument, you are as good as making a bet that the company making the payments doesn't fold.

What? Taking note of the risks, knowing they were insanely high and still choosing to splunk down a load of 'cash'/whatever to proceed and then losing said cash is exactly gambling.

Bankers were placing bets that their institution could not hope to cover if they failed. They failed.
It all went tits up.
If that's not gambling, the dictionary is wrong.