stop out occurred on 78% of testing interval

Ok, so I think I have a pretty good EA but if I am trading all of currency pairs 3 of them show that I lose money. When I run the currency pairs individually the ones that lose money show this stop out occurred. What does that mean? I thought it meant the end of the test but wouldn't that show on all currency pairs not just some. Does it mean that the other currency pairs ended positive because the deal was completed and the negative ones the deals didn't complete. Thanks for any help.