More than a million Americans a month opened a brokerage account with Robinhood in the first quarter of this year, most of them new to trading. The attraction: Robinhood charges no commission at all and you need just $1 to open an account. And now, as you can see below, it is coming to the UK this year. Great news or worrying news? It depends who you are. I start with my long held belief that traditional retail brokers like Hargreaves Lansdown (HL) and AJ Bell (AJB) rip folks off with execution only charges that are far too high.