Red Hat's revenues are a little short of 3 billion (though growing fast), and the market cap is about 15-20 (going by memory). That is with a full software stack going from IaaS to containers to application server. Right now containers are the thing, but what if they are going to become commodity in 5 years? And can the Docker brand compete against the Google and Red Hat brands that are also selling container management platforms (fully open source in the case of RH, no enterprise features and no lock-in)? It seems like a very generous valuation.

Disclaimer: working at RH