Insiders are selling shares to private wealth management firms / asset management firms. It's amazing how much hype can do in the private finance world when you have the perception of momentum and herd mentality. Look at Clinkle raising $30mm ... this is the same thing happening at a bigger scale. Look at Groupon... same thing.
Here's one to S F Sentry Securities, Inc. http://www.sec.gov/Archives/edgar/data/1321655/0001321655140...
Morgan Stanley took over $25mm in fees to arrange these sales... the reason for that is because they know that there is no way Palantir is going to have an IPO in the near future -- or else they would be salivating to do this kind of transaction for free to gain favor with management.
The fundamental problem with Palantir is that they are a government contractor masquerading as a product company. $200mm in government contracts comes with enough overhead that there is not a ton of margin. You can see tons of defense contractors in the midwest doing hundreds of millions in revenue.
Take a look at their revenue numbers for federal government (which is likely a major portion of their ~$420mm in revenue): http://goo.gl/v7JzT5 http://goo.gl/AzZeuR