Margin Maintenance (a) If at any time the aggregate Market Value of all Purchased Securities subject to all Transactions in which a particular party hereto is acting as Buyer is less than the aggregate Buyer’s Margin Amount for all such Transactions (a “Margin Deficit”), then Buyer may by notice to Seller require Seller in such Transactions, at Seller’s option, to transfer to Buyer cash or additional Securities reasonably acceptable to Buyer (“Additional Purchased Securities”), so that the cash and aggregate Market Value of the Purchased Securities, including any such Additional Purchased Securities, will thereupon equal or exceed such aggregate Buyer’s Margin Amount (decreased by the amount of any Margin Deficit as of such date arising from any Transactions in which such Buyer is acting as Seller).