Stock trading is at a record high in the US these days, but the small investors who flooded into the market earlier in the year are largely sitting on the sidelines, according to new data.

Stung by losses in their favoured technology stocks, retail investors have dramatically reduced their trading from the frenzied levels at the market peak in March.

At some online brokerages, trading activity shrivelled by almost 50 per cent from March to August. Although it has perked up modestly in the past two months, trading is still down by more than one-third at some companies.

That stands in stark contrast to volume in the broader market. Last month, for example, trading volume hit a record as a combined average of about 3.1 billion shares a day changed hands on the New York Stock Exchange and Nasdaq.