It gets complicated. Say the market restricts quotes to say every 10ms, and you want to quote a price just before the time of a news event. If you quote a "regu

It gets complicated. Say the market restricts quotes to say every 10ms, and you want to quote a price just before the time of a news event. If you quote a "regular" price then you might get screwed when the news comes out which has an impact on the price and you can't pull your quote from the market. So you end up either not quoting a price at all or quoting a much worse price to protect yourself from the news. In either case you result in worse pricing for everyone. Shrinking times also have the advantage of improving price precision, when your talking about price moves over a very small period of time we can often be talking about very small price moves (say one-thousandth of a cent) which helps everyone. When before something may have been worth 213.314 you may have only been able to sell at 213.31, which for large deals can have a significant impact in high-volume markets, but with higher precision prices are more accurate.