Also, extrapolating without much explanation means squat.

http://xkcd.com/605/

Applies to teenage prodigies too.

I should write about the dancing monkey problem sometime.

This is worse than hand waving. It is the kind of static typing error one gets when using Astrology to reason about money.

You just cannot compare the value of a projection/guess that doesn't account for inflation with the current instantaneous GDP value (thus completely ignoring the fact that money today is worth more than in 2020) while at the same time not projecting Brazil's current value.

It's a [failing] attempt to make sense of hard figures. Pretty much like 3 times the distance between earth and moon.

Surely if the journalist actually thought Apple stock would increase in value 6 fold in the next 8 years they'd buy it. (And then put a disclaimer on the article.) If the market shared their opinion then it wouldn't be available to buy at such a low price.

Apples and Oranges. The GDP is the income of a country (roughly), the market cap is more than the current annual income of a company. Not at all comparable.

Indeed. Makes me wonder what France or Brazil are worth.