Imbalance Accounts include:

• Cumulative
• Operating
• CPBA

Imbalance Account balances are current only during the Trade Period.

Balance Accounts include:

• Market Center Park & Lend
• Storage

Current Balance Account balances may be retrieved at any time, whether the Trade Period is in effect or not.

Three types of imbalances may be electronically traded:

• Cumulative Imbalances - traded the month following the supply month
• Operating Imbalances - traded three months following the supply month
• California Production Imbalances (CPBA) - traded the month following the supply month