but up until the 1680s or so were very few shares and almost never traded for the east india company, the hudson bay company, royal african company which was a slave trading company. they existed and they were in fact companies that had shares that in theory can movebetween people but they very rarely did . >> they tended to be bought and sold by a small group of people . >> and in the 1680s, that started to change and in the 1690s it changed rapidly and there was a lot of new companies formed to try all kinds of things. mining companies, insurance companies, they called this period the 1690s roughly 1750 , it's called the financial revolution. it's a term of art amongst historians of the time. and one of the arguments in the book is to understand the financial revolution simply as part of the scientific revolution. there was a large intellectual transformation going on and the people doing them in separate today i'm being a banker and tomorrow i'm being a financial revolutionary. it's why you get people like edmund halleyworking out the math of life insurance . , newton himself writi