Next Monday, 26th May, is a public holiday in both the U.K. and the U.S.A. The U.K. and the U.S.A. are the major financial centers driving volume in the Forex market, so we can expect this day to have very low volatility and price movement.
For this reason, we do not recommend opening any new trades whatsoever after 5pm Friday London time, until 8am Tokyo time next Tuesday, 27th May. It is of course acceptable to close trades, as if a stop loss is exceeded during such a slow period, it would be very likely to also be exceeded during an active market.
One possible exception might be if the European election results produce a dramatic and unexpected result, which could affect the Euro. The results are due late on Sunday evening U.K. time. If the strongly anti-E.U. parties win more than 20% of the seats, and there are strong anti E.U. votes in the U.K. and other major member states, this might affect the Euro negatively for a while. As always, extreme caution should be exercised before entering any trades on such a holiday.
Please be aware that most retail Forex brokers will allow trading during normal market hours next Monday, 26th May. Those based in the U.K. or the U.S.A., however, may have somewhat curtailed customer support. If you can possibly wait or avoid requiring active support from your broker over this period, you should eventually receive a more prompt and convenient service on the following day.