Brexit just cost the U.K. its perfect "AAA" credit rating.
Standard & Poor's downgraded the U.K. by two notches to "AA" on Monday, the latest fallout from last week's shocking U.K. referendum to leave the European Union.
S&P warned that Brexit will "weaken the predictability, stability and effectiveness" of British policymaking and deter foreign investment in the U.K. The ratings firm said Brexit may also lead to a "deterioration" of the British economy -- especially its vitally-important banking industry -- and could even trigger a "constitutional crisis" if there is another referendum on Scottish independence.
S&P kept a "negative" outlook on the U.K., signaling more downgrades are possible. The ratings firm said another downgrade could be triggered if the pound sterling loses its status as a leading reserve currency, public finances deteriorate, the British economy slumps more than feared or if Scotland holds a referendum.
Brexit has changed the equation so much that S&P said it no longer considers Britain's institutions to be a strength.
