STP-79: What should the guaranteed amount be increased to, in order to cover the results of the recent auction for both Ameren and ComEd?

For the energy contracts, ComEd and Ameren Illinois do not specify any amount since typically no credit exposure exists when the contracts are signed. If, after signing, credit exposure develops, the Company will send the Winning Bidder a margin call notice. Winning Bidders may, at their option, provide a nominal amount for a guaranty in case market movements result in credit exposure.