If short trade is not an option then you should do long trades and hold instead, you should also consider that some of those coins might be pumping for now but in the long run they will collapse someday you might even see those coins getting delisted to that exchange, if you've done deep research to those cryptos then you can safely assume that they are good for long-term goals and profit, lastly consider a decent exchange if you are not confident to the recent one.
Sometimes it goes up then suddenly it will go for a huge dip again then go for a bull run. that is why its hard to invest for short term now and expect for a huge profit just by doing it .
in any case, today due to the poor state of the market for a good profit from short-term investments will not have to wait. I very much hope that most promising projects will not lose their relevance and the current state of the market will not affect their development.