A Pending Order is an order to buy or sell a financial instrument in future under pre-defined conditions. These are the following types of Pending Orders: 

1. Buy Limit: a trade request to buy at the Ask price that is equal to or lower than that specified in the order. The current price level is higher than the value specified in the order. Usually this order is placed in anticipation of that the instrument price, having fallen to a certain level,  will increase. 

2. Buy Stop: a trade order to buy at the Ask price equal to or greater than the one specified in the order. The current price level is lower than the value specified in the order. Usually this order is placed in the anticipation that the price will reach a certain level and will continue to grow. 

3. Sell Limit: a trade order to sell at the Bid price equal to or greater than the one specified in the order. The current price level is lower than the value specified in the order. Usually this order is placed in the anticipation that the price will increase to a certain level and will fall. 

4. Sell Stop: a trade order to sell at the Bid price equal to or less than the one specified in the order. The current price level is higher than the value specified in the order. Usually this order is placed in the anticipation that the price will reach a certain level and will keep on falling.

5. Buy Stop Limit: this type is the combination of the first two types, being a stop order and to place a Buy Limit Order. As soon as the future Ask price reaches the stop-level indicated in the order, a Buy Limit order will be placed at the level specified in the the Stop Limit price field. A stop level is set above the current Ask price, while Stop Limit price is set below the stop level. 

6. Sell Stop Limit: this order is a stop order to place a Sell Limit order. As soon as the future Bid price reaches the stop-level indicated in the order, a Sell limit order will be placed at the level specified in the Stop Limit price field. A stop level is set below the current Bid price, while Stop limit is set above the stop level.