“My father was a racehorse trainer and gambler. That was my training,” explains Christopher Dennistoun, peering over his specs and leafing through a limited edition of Jesse Livermore’s How to Trade in Stocks.

The two aspects of his professional life – “I speculate, I deal in books a bit” – have dovetailed neatly in the amassing of what is, at more than 750 titles, probably the world’s largest and most comprehensive collection of books on financial speculation. “I never set out to build anything definitive,” he says, surrounded by everything from rare first editions to even rarer brokers’ sheets, pamphlets, ticker-tape and the like. “I just wanted to read around the subject and collect some books, found I had reached a critical mass, and then the internet happened.”