"Systems" in this context isn't referring to IT security, rather economic systems and technological adoption patterns. This book is more like a survey of necessary concepts that business people will recognize that are relevant to bitcoin. The book lays the philosophical and state-of-the-art foundation required to fully understand why bitcoin is a viable and better alternative to our fiat system of money, and what to expect from the news and the markets during its widespread acceptance. I purchased this book with lightning and expect to finish it this evening. The inclueed slide deck is a very helpful overview, highly professional.