The following margin rate changes will become effective with the mid-day calculation on Friday, August 22, 2003:

CBOT Margin Rates	From	To
Oats	$500	$400
Rice	$650	$750
10-Year Agency Notes	$1,500	$1,900
10-Year Treasury Notes	$1,350	$1,500
Mini-10-Year Treasury Notes	$675	$750
30 Day Federal Funds	$400	$300
10-Year Interest Rate Swap	$1700	$1900
5-Year Interest Rate Swap	$900	$1100

	From		To
CBOT Inter-Commodity Spread Credit Rates	Spread Margin %	Spread Savings %	Spread Margin %	Spread Savings %
10-Year Treasury Notes vs. 5-Year Treasury Notes (1:1)	20%	80%	25%	75%
Mini-10-Year Treasury Notes vs. 5-Year Treasury Notes (2:1)	20%	80%	25%	75%
10-Year Treasury Notes vs. 2-Year Treasury Notes (2:3)	30%	70%	35%	65%
Mini-10-Year Treasury Notes vs. 2-Year Treasury Notes (4:3)	30%	70%	35%	65%
US Treasury Bonds vs. 10-Year Agency Notes (1:2)	25%	75%	30%	70%
Mini-US Treasury Bonds vs. 10-Year Agency Notes (1:1)	25%	75%	30%	70%
10-Year Agency Notes vs. 10-Year Treasury Notes (1:1)	20%	80%	25%	75%
10-Year Agency Notes vs. Mini-10-Year Treasury Notes (1:2)	20%	80%	25%	75%
10-Year Agency Notes vs. 5-Year Treasury Notes (2:3)	25%	75%	30%	70%
10-Year Agency Notes vs. 2-Year Treasury Notes (2:3)	40%	60%	45%	55%
10-Year Interest Rate Swap vs. 10-Year Agency Notes (1:1)	25%	75%	15%	85%
5-Year Interest Rate Swap vs. 10-Year Interest Rate Swap (2:1)	20%	80%	15%	85%

Should you have any questions, please call or e-mail one of the following Client Services and Support Representatives:

John Compall		john.compall@clearingcorp.com
Marc MacQuarrie	786-5732	marc.macquarrie@clearingcorp.com
Molly McMahon	786-5731	molly.mcmahon@clearingcorp.com
Jill Turner	786-5718	jill.turner@clearingcorp.com
Thomas Andrews	Director	thomas.andrews@clearingcorp.com
Client Services and Support E-Mail Address		css@clearingcorp.com
Clearing Corporation Web Site		http://www.clearingcorp.com