The clue as to why the London Stock Exchange has risen sevenfold in value in the past seven years is not contained in its name. The best days of being a stock exchange are in the past, when they were near-monopolies owned by market-making members and could easily make money. That was long ago.

But a funny thing happened on the way to their demise. The businesses formerly run as stock exchanges became more valuable despite a wave of disruption unleashed by regulation, technology and competition. They should be in trouble but the leading ones have instead been transformed.

This phenomenon is on show on both sides of the Atlantic. The IEX trading platform, made famous by Michael Lewis’s book Flash Boys, has applied to become the 13th US stock exchange. The buttonwood tree under which 24 brokers agreed to form the New York Stock Exchange in 1792 has become a forest of competing bourses.