On another note. Investment books are such a scam. There seems to be a book for every investment strategy. So one guy write a book to invest in gold, the next one in real estate, next one in shipping companies and then even more esoteric stuff like Bitcoin, Bitcoin Mining, Weed stocks etc. It seems like the only one making money with all these strategies is the author selling books.
These books are designed to scam retail investors.
Next thing on my bucket list is writing a book called “Buy low and sell high - how to make money in the stock market” 
Edit: lol someone had the same idea and just self published it https://www.amazon.com/Buy-Low-Sell-High-comprehensive/dp/1535293551 (Do not buy!)