Banks and brokers are ripping off the taxpayers who bailed many of them out, according to an influential UK consumer lobby group.
Finance Watch has raised the heat in an increasingly impassioned debate by arguing that ordinary people saving through pension funds or equity-based investments are losing out through the activities of high frequency traders (HFTs).
They use computers to execute huge numbers of trades in short periods of time, and exchanges have spent millions of pounds to upgrade their infrastructure to accommodate them. This is likely to be made clear when the London Stock Exchange reports results at the end of the week.
Benoit Lallemand, senior research analyst at Finance Watch, said: "Many high frequency firms make huge profits. But if someone is making profits like this, there has to be a loser."
Lallemand said that high frequency traders are effectively making profits on the back of the man in the street. He added that ordinary investors were losing out twice.