Unlike units in a conventional mutual fund, ETFs can be traded all day long.
不像传统的共同基金单位，ETF可以整日交易。
2
Since June, about 31 million of them have been traded on a typical day, more than triple the average for Goldman Sachs shares.
自从今年六月，每日成交量将近三千一百万股，比高盛公司股票的每日平均成交量要大三倍还多。
3
The key is then divided into dozens of pieces and sent out over peer-to-peer (P2P) networks - the same ones where music and movie files are traded every day.