Contract of Difference does not have an expiry date like options or futures contracts. As opposed to an expiry date a Contract of Difference is effectively renewed at the close of each trading day and rolled forward if desired - you can keep your position open indefinitely, providing there is enough margin in your account to support the position. There is no restriction on the entry or exit price of a Contract of Difference, no time limit is placed on when this exchange happens and no restriction is placed on buying first or selling first. Contract of Difference is traded on leverage to give traders more trading power, flexibility and opportunities.
One of the great features of CFD is that you are able to trade on both the long and the short side of the market example you can choose to 'long' or 'short' a position. If you are long, you receive dividends and pay interest, if you are short you do the reverse. It is worth noting that commission is paid on either side of the contract and you can close a contract at any time.