Foreign currency and futures markets trade about 24 hours per day. They close down at 4:15 ET on Fridays and open back up for the week at 6 pm ET on Sundays.
OANDA is one of thousands of brokerage firms. For market advantage they choose to open their trading desk at 6 am on Sundays, 12 hours ahead of the competition.
On Sunday Greece is voting on whether to abide by the austerity measures and remain a part of the Euro. This has the potential to be a huge market-moving event.
OANDA has chosen to delay its opening of their trading desks by nine hours, they are not closing down for the day, they are readjusting their hours with the rest of the competition. I’m assuming this is being done to protect their clients from huge unknown market swings with very little market volume.
While I do believe the Euro is going to fail in the near future and we will likely see a dramatic difference in the market, I personally believe there will be a succession of events that creates the collapse. Could this weekend be the catalyst for such events, yes it is possible. But, in my estimation this article reflects a one-time protective measure by a single brokerage firm and does not, by itself, indicate a potential collapse of the Euro this weekend.
Discretion in any action on your part regarding your personal funds is highly advised.