1.   Exchanges often raise margins in times of increased volatility.

2.   Exchanges often raise their margins in times of increased volatility.

3.   If anything, the Internet will give consumers more power and make it hard even for firms with a large market share to raise their margins for long.

4.   In addition, the exchange raised the margins on its coffee contracts following a recent increase in volatility and prices.

5.   On the domestic front, by controlling costs, it raised operating margins to some of the best reported in the industry.

6.   Some experts argue that the Fed should raise the margin.

7.   Some have advocated raising margins as a way to keep stocks from rising to unsustainable levels.

8.   The monopoly works to raise operating margins as well as to increase demand.

9.   The New York Mercantile Exchange said it will raise the margins on natural gas futures contracts at the close of trading Monday.

10.   The New York Mercantile Exchange said it will raise the margins on natural gas futures contracts at the close of trading tomorrow.