You are right. If a person has the right knowledge, the right knowledge of the strategy inside him, then he will never be afraid of the market going up and down. Since he has the ability to analyze the market completely, he can analyze it correctly with his maximum knowledge and invest correctly for a short time or a long time. Although he loses some amount of his money, he has the right knowledge and ideas to recover his money. So I think for a professional investor, no matter what the market is like, he will not be afraid of being in the market, but he can continue to invest with his own knowledge.
If you are investing in the short term, then you have to analyze the market. In the case of long term investment, you have to continue buying continuously by relying on your discretionary income. You should continue buying continuously until the goal of building your portfolio is met.
Take note that you don't needs to analyze the market as a Bitcoin investor, just buy once your discretionary income is available because the price of Bitcoin now is still very cheap comparing to how much it might be in ten to twenty years time from now, so why analyzing?
And secondly, their is nothing as a short term investor, it's either you are a long term investor or a trader that buys with the intention of selling for minimal gains in a very short time interval, so in my own opinion, those people that buy and sold their Bitcoin just because it appreciate in value are not investors, they are traders that sold for minimal gains.
Finally, when it comes to investment in Bitcoin, the best way to go about it is to think only long term because the way Bitcoin is wired, you can only reap the full dividend of your investment when you buy and hold for a very long period of time, not minimal gains that wouldn't have any significant impact on your financial status.