1. Unrealistic profit expectation
Unrealistic profit expectation is the common problem for novice traders as they are speculating huge profits without financial calculation with proper tested strategy.
This is important for newbie traders as I know most will still be having this issue and even older traders. This cause of this is greed. If we become greedy, there is a big trap waiting at the front that we can be trapped. So is better to set realistic profit goal at every trade order we make.
I would even go one step further and say do not expect profits at all first month of trading and just focus about learning how to read graphs and while with bitcoins it is pretty obnoxious to accurately read graphs but some patterns can be depicted from it and used for trades, for example a halving usually brings a price increase due to the fear of missing out it brings to bitcoin users.
With trading I have learned that it is not as important to make money quickly as it is to gather knowledge and developing an ability to understand reason behind the fall and rise of any assets. I mean recently bitcoin went so down people were worried but some wise guys who had good reasoning why it felt down also knew it would get up very soon and made some investments accordingly and while profits are temporary the knowledge you gain about trading is permanent.