There is nothing wrong to do this (gambling) with small amounts of money, but there is also a need to have enough cashflow coming in to be able to pay for expenses.. and surely sometimes, someone might have a small portion of their investment (such as less than 10% or there might be various ways to measure how to put limits on oneself) that they put into a kind of bet that the price will go up and then they will have a plan to cash out at a certain price or within a certain timeframe that it taking chances, but maybe they are taking chances, but not so much chances that they are not able to cover their little gambling inclination.. yet part of the problem is getting carried away and doing too much.. which is not always clear about going too far until an emergency situation comes and there is a lack of preparation for the emergency situation because too many of the emergency funds were put at risk.
For my own personal opinion, I think it's best not to even try and trade some of your Bitcoin for extra earning because I think that's where you are driving at because I doubt if you won't be carried away if actually you secured some little at trying one or two times, there is no guarantee that it will continue and that would be risking your Bitcoin because if the whole situation turns sideways and instead of profits you amount loses then for sure you if didn't plan well you will definitely end up touching your holding just as you mentioned to solve unexpected events as the money for such was not properly set for.
Unfortunately, many traders are trapped in this process. At the beginning, trading seems so easy as you will easily make profit for the method you have adopted. This initial ease of profit is what make many people to discard risk management and be overwhelmed by greed under the pretext "easy money". It is after a while it begins to get tougher for the trader as everything will magically begin to fail, the once efficient strategy will become a losing pathway. At this point, the trader will seek a new method and the cycle continues.
The challenge with trading is consistency. This is where many traders fail, hence, why trading is very risky. It is actually few traders that have achieved consistency in trading and are actually making profits. The rest are winning and losing and at the end, the capital is being depleted.
So it is safer to go with long term holding that requires minimal efforts and can yield greater returns with lesser risk exposure.