Consider_this

British Pound Crumbles

dieuwer is on the right track. It's just that timing's the bitch.

This is a collective race to the bottom. Pretend there're only 2 currencies in the world (pounds and usd):

First a currency, say pounds, will get trashed relative to the other one.

Then USD, will get trashed too, until it sorta catches up with pounds.

Then pound will trash again. Rinse and repeat.

This is how a fiat currency system ends, not by excess of money or lack of goods as goldbugs would have you believe: but by excessive volatility that leads to collapse.

The volatility swing will grow bigger and bigger. Like an unstable system that resonates uncontrollably with increasing power. The swings will eventually kill the fiat currency system, as nobody can trade with wild swings in currency.