Rather than cry ‘fire’, someone needs to explain this in terms people can understand. (That means a 2 minute byte)
Company A issues a bond.
Company B places a bet that Company A will default on the bond.
Company C takes B's bet and similar bets from lots of other companies.
Company C books enormous profits on the business.
Company A defaults on the Bond.
Company B is rich.
Company C is up the creek.