Let us assume a coin called X is moving within $1.2 to $3 for many weeks, you think that its price can not get to 2x. You used that to open a long position with your $100, thinking it can not get to $6 from $3.
That means you think the price of the coin will be falling or later fall after getting to $3. You set 1x long position which mean the liquidation would be around $6.
In just less than an hours, the coin trading volume suddenly increase which make the coin X to move from $3 to $10 within 45 minutes, but your money got liquidated at $6, which means even going for slightly lower than 1x leverage still can result to liquidation.
Has it happened to you before? Volatile coins trading is very risky
First things first, you have made a mistake in your post by mentioning "long position" instead of "short position" as mentioned by @Odusko as well. You should edit your post and rectify that.
That being said, there is no doubt that futures trading is extremely risky, especially if you are trading extremely volatile cryptocurrencies. We often say that futures trading is for experienced traders only, and those with no experience and less knowledge can barely survive in it, but even experienced traders can lose money if they trade coins such as the one you mentioned.
When someone wants to take the risk of trading such coins or tokens, they should at least use proper stop-loss with their trades so that they don't lose all the capital they have used for such a trade.