A new investor only needs to believe in bitcoin after checking the price history of bitcoin and see that the price of bitcoin going up in future has high odds than it going down because bitcoin is still going to mature more and more overtime.
No, i don't expect an investor to believe in Bitcoin by just checking the price of Bitcoin in the past or currently. He must understand the nature of Bitcoin, and grasp knowledge from it. Only then he will have his personal conviction on Bitcoin and believe in it. The price being assured to go up for years than going down is what build trust to choose it as the best asset to invest in. But believing is witnessing. When we start to invest with the knowledge we have and things start working out properly based on our goals, strategies and longevity then we are not true believers because we would rather trust in holding it for more than 10 years rather than trusting it in the short term
Seeing the previous situation does not only have to be fixated on prices but in the end we realize that as long as bitcoin is created, the movement in terms of progress has looked very good so that by looking at this of course we will have another view.
Although it is not wrong when we look at the price in the end but it also will not change anything because bitcoin at the beginning of their period has become past history and we only have to focus on looking at the future with the conditions that are happening now so instead of daydreaming with past prices it would be better we only have to focus on preparing for the future we want.
For as a belief, it is actually not wrong when we have to see some of the things that happened before but it is not used as a hope that we go there but as proof that bitcoin's progress is indeed very good.