We need to know that every transaction is executed due to a match of the supply and demand, as simply, the transaction was made if a seller and buyer were transacting on the match price.

Limit method order hasn't been executed due to : 

• Market price has not yet matched your price
  Your pending order will be executed when the price matches the market price
  For example, you make a BTC order buy at 500,000,000,- IDR, meanwhile the BTC market price is currently on 600,000,000,- IDR.
  So your transaction only will be processed if the current BTC price drops to your order price.
• The volume of transactions at the same price as you specified is not sufficient
  Transactions in the order book are a collection of transactions from members, so a price likely consists of orders from several members.
  Orders at the same price will be executed according to the queue until the existing order volume runs out. For example, in the BTC market, there is a buy order for Rp. 500,000,000, - as much as Rp. 20,000,000, - from 2 different members, each ordering Rp. 10,000,000,-, while in the sell order there is only a sell order at the same price of Rp. 10,000,000,-.
  So that this transaction will only be executed in the amount of Rp. 10,000,000,- belongs to the purchase order member who made the order first.
• Split Transaction
  If your order transaction is only partially executed, you don't need to worry. In the explanation of the previous point regarding market volume, it can be seen that the transaction will be executed if there is sufficient volume.
  This split transaction is because the volume on the market at the price you specify is not sufficient to process the entire order. You can wait until there is a sufficient volume of transactions at the price you specify for all orders to be completed.