Open Book Love Machine 16 years ago Open Book Also called: unmatched book, short book. Circumstance where bank has short term liabilities and long term assets creating imbalance. Random Finance Terms for the Letter O One-Way Market OPEC (Organization of Petroleum Exporting Countries) Open Account Open Interest Open Book Open Contracts Open Interest Open Listing Open (Good-Till-Cancelled) Order Recommended for you: Open Contracts Open Interest Open (Good-Till-Cancelled) Order Open Account