I just want to take everyone in the Valley aside and sit them down, look into the crowd and calmly say "Hey guys, if we could please stop overvaluing every company that manages to set up a simple CRUD site with no revenue model, that would be great. Let's do ourselves a favor and not re-do the DotCom bubble. Thanks all and have a good night."
Assuming from your username that this is your site, sorry if that's wrong. Anyway, how do you define a "startup"? Some of these companies are over a decade old (eg Atlassian), some have over a $B of funding (eg Dropbox), and a couple (Box, GoPro) seem to be pretty much at IPO. Also they're all in America, is that intentional or could you genuinely not find any non-US startup valued at over $225M?
The list is pre-IPO / private tech companies. There are several non US companies on the list - e.g., Spotify, Atlassian. Also, note that you can sign up to add or edit companies. It's a collaborative list and dynamic. Thanks for the feedback.