I don't know if you mean buying during the pre-market phase, but this method didn't work for me. I tried buying some coins during the pre-market phase, and when they were listed, their value was lower.
I'm not sure if it's the same, but this method didn't work for me, so I abandoned it. Most of the projects I followed saw their value drop immediately after listing. Perhaps the only chance is to sell immediately after listing. You have to be very quick.
That is the trick, it may not work some people if you pick the wrong ones, and that is exactly why I am not doing it as well. If I did this, then I am pretty sure I would just straight up lose money for the long term and that won't be easy, but if I know what I am doing then it should not be all that easy to handle this and we could have some trouble with it. I get that it may not be easy to fix this, but we need to spend time on learning how to be better at it ,and that means losing money until we get better.
I am not going to do it, and I do not think that we could have any good future if we just keep losing. I avoid it, and I try spot trading and long term investment as my way of making money, which is better.