Definitely. I have taken 1% in a month on a trade. Actually I have come out of a trade flat after a week. I have come out with %15 loss in 4 months!!!!!!!!!!!. Time does not have any meaning. If you think that you should get out, get out.
I interpreted the question as a risk-free 4% trade in three days, and that's of course a "yes". This does not mean I would necessarily take my profits after 4% gain on any random trade - that is much too complex a situation to just say yes or no.
What I mean is you sorta feel it'll go up higher, but who knows it could chop around and go back even. And if it goes up to where you think, it could be another month or so!!