Why Black Wednesday still matters – it was the start of markets telling politicians what to do

I spent Black Wednesday – the day the markets successfully bet against the power of the British government to prop up the pound sterling – on the 28th floor of Dresdner Bank’s headquarters in Frankfurt. I had just been hired as an exchange-student intern in the back office for currency options and interest rate derivatives. Though all days on the trading floor were busy, I had never seen anything like it before.