You can still try to close any trade, but you will be warned if the oldest trade of the currency pair and unit size needs to be closed first. (oanda.com)
Finally, it is important to note that in leveraged forex trading, margin privileges are extended to traders in good faith as a way to facilitate more efficient trading of currencies. (forex.com)
Although the cryptocurrency Bitcoin was introduced in the year 2009, the active trading of these currencies didn't commence until 2011. (globalcoinreport.com)