To ensure that no single company dominates trading, they are capped at a maximum of 15% for value, volume and transactions.
When smaller orders dominate trading, it is more likely that a single order will move the price of the stock, increasing investors' costs.
The dollar rose against most currencies, but it was the strengthening yen that dominated trading.
Fears about the domestic economy and the currency crisis will clearly dominate trading in the coming months.
But their role faded in the late 1960's and in the next couple of decades, as institutional investors came to dominate trading.
Indeed, a number of analysts and traders said that technical factors tended to dominate trading yesterday.
Once again, concern about higher interest rates dominated trading, analysts said.
Traders said the Japanese yen continued to dominate trading while the dollar kept to a tight range.
Still, some analysts seemed to be betting that an overall sluggishness would dominate trading.
With no important economic news as a backdrop, technical factors dominated trading.