i will poll for both, as you need a good skill for success and if you do not lucky your skill even cannot enable you to succeed. therefore both are important for success.
Well experienced traders don't need luck to make profit. Of course, if luck can help you in getting more profits than usual in some cases, then it's of course more than welcome. But it's not something they partly depend on.
I would say that even they are going to be experienced traders already they still need to depend on luck and I would say they need both of it.
That is just like a pair of shoe you can't go on if you only have 1 shoe on your left and you don't have on the right.
So I would go for both of it.