By Rupert Hargreaves “Why is it,” Gerald Perez, the UK boss of global brokerage giant Interactive Brokers, told City A.M., “that UK investors can trade anywhere around the world on our platform for less than £3, but other platforms charge £10 for investors to trade in their home market?” Although it’s currently a fairly small player in the UK market, the company has set its sights on growth in the country, and if peers aren’t already worried, then they should be. Interactive Brokers takes Wall Street by storm Interactive Brokers was founded in 1977 by Thomas Peterffy, who remains chairman of t…