The Current Vulnerability Landscape: What Should You Be Most Worried About?

Cybersecurity over the past few years has been getting more exposure as a mainstream topic in the media, mostly due to data breaches of very well know consumer related brands as they impact most of our day to day lives, such as Facebook, Target, and Equifax.  
But what are the true stats and trends behind these breaches, what are the types of vulnerabilities these companies are leaving exposed, and what is the true cost to companies?