A central limit order book (CLOB) was a centralised database of limit orders proposed by the Securities Exchange Commission. However, the concept was opposed by securities companies. A Central Limit Order Book or ("CLOB") is a trading method used by most exchanges globally. It is a transparent system that matches customer orders (e.g. bids and offers) on a 'price time priority' basis. The highest ("best") bid order and the lowest ("cheapest") offer order constitutes the best market or "the touch" in a given security or swap contract. Customers can routinely cross the bid/ask spread to effect low cost execution. They also can see market depth or the "stack" in which customers can view bid orders for various sizes and prices on one side vs. viewing offer orders at various sizes and prices on