As a whole, investors should welcome attempts to safeguard the integrity of markets. You need very clear rules applied to markets.

America's downgrade may serve as a wakeup call for its policymakers. It is an unambiguous and loud signal of the country's eroding economic strength and global standing. It renders urgent the need to regain the initiative through better economic policymaking and more coherent governance.

It is hard to imagine that, having downgraded the US, S & P will not follow suit on at least one of the other members of the dwindling club of sovereign AAAs. If this were to materialise and involve a country like France, for example, it could complicate the already fragile efforts by Europe to rescue countries in its periphery.

The one instrument that has relative political autonomy is monetary policy. Central banks do not need to go to Congress to get approval for an interest rate hike.

Investors have to ask themselves two questions. How much can we grow our investments? And, can we afford our mistakes?

How long can interest rates stay negative? Think about this. Not only are you lending your money to governments, but you're paying them interest for the privilege of doing so.

We normally think if you're going to lend someone money, you should get some reward for doing this. In Europe, it's a tax!