[zjaffee]

There are many companies over a 100 years old who are still in the fortune 500, many of them have very strong market cap's.

Look at GE, or JP Morgan. http://fortune.com/2015/06/10/oldest-companies-fortune-500/

It's just the case that old companies aren't generally coming out of nowhere and all of a sudden turning everything around, part of the reason what apple has done over the past 10 or so years so impressive.

[ethanbond]

I didn't say there aren't any. I said that the markets aren't dominated by them, i.e. there is obviously such a thing as a large company declining, and it is obviously a common enough thing for there to not to be thousands of gigantic century-old companies among us.

It's plainly absurd to say "a company is big therefore it will grow." In my reading of the original comment I ignored the caveat of the 5-10 year timeframe. It's true that a gigantic company can almost definitely decline for 5-10 years without disappearing. It's not true that that means it will grow for those 5-10 years instead.