but where will btc find new buyers when it has reached 100k and needs to go up another 100k in order to double again in price?
I guess that there is a misunderstanding on how human psychology works.
The faster the price grows, the more the news advertising this attracting more new buyers, many of them ignoring the risks.
Of course, many of them will sell lower than they've bought when the FOMO bubble bursts, but the ones with patience and who have invested money they did afford to lose will be happy and wise when the next cycle will go on.