China & India to surpass US economy by 2030

There were several articles in Britain during late 18th century stating that Sun will never set in its empire.

 

It has happened before, will happen in future. Empire's fall and new one will take over

 

I think you misunderstood the article. You are using the GDP in current $, where as the article is quoting GDP in PPP (Purchasing Power Parity).

China has already past US in GDP PPP couple of years back.

 

OK, I stand corrected. But that means there is an opportunity to arbitrage to make some money?

 

Not in the way of buying Big Mac there and selling Big Mac here. It is not arbitrage, but if you can identify the companies early which cater to the growing middle class consumers in those country, then yes.