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.

Once you start moving [market] lower, then you trigger of all sorts of things. You trigger people who have to sell because they're over-levered. So they sell their winners and their losers. They're just trying to raise cash. So, what you then get is spreading malaise throughout the global markets.

Investors should invest on what they know. The biggest mistake is to invest on what they don't know.

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

If you happen to be the only one with negative interest rates, you also weaken your currency, which means you make your exports more competitive.

As we spend more, and as companies are pushed to invest, they say, "Hey wait a minute! There's more demand in the system. Let's invest more."

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.