Nokia

Nokia's fall from the world's #1 phone maker (controlling 40% of the global mobile phone market in 2007) to irrelevance by 2013 is the most dramatic collapse in technology history. Having dominated the mobile era for a decade, Nokia failed to respond to the iPhone's 2007 touchscreen revolution. Internal culture problems, bureaucracy, and reluctance to adopt new operating systems led to its mobile phone business being sold to Microsoft for $7.2 billion in 2013 — a fraction of its peak value.