These comparisons are almost meaningless - e.g. Apple is worth about the same as Korea's stockmarket, almost as much as China's.

Also, some of the most valuable companies are not listed on any stock market, so the stock market is not necessarily any kind of full picture of the worth of the country. For example: http://www.ft.com/cms/s/2/5de6ef96-8b95-11db-a61f-0000779e23...

Yeah, Saudi Aramco 2005 is still worth more than Apple right now.. but oil has fallen so maybe this has changed.

Rather than meaningless, it's amazing.

Apple is not worth anywhere near as much as China's stock market however. The Shanghai Stock Exchange all by itself is worth several trillion dollars.

Why is that meaningless?

Because, in addition to jhallenworld's point that not all economically relevant companies are publicly traded, not all publicly traded companies are listed on exchanges in their own countries.

Actually, Microsoft is now worth more than the entire Russian stock market, too.