I just wonder if you want to earn in bitcoin investment then a smart investor would invest in while bitcoin is cheaper and not the current price.
Is there any reason we can think of why people love to invest in bitcoin while market price is high?
What makes you think the current price is not cheap?
The ATH price is 20 thousand dollars. We are at 14 thousand. I could argue that compared to the ATH the current price is cheap as it's almost 30% cheaper than the top price.
I invest because we are in a bull market and based on the past performance of Bitcoin I expect the price to go beyond the last ATH in this bullish wave.
I agree with you. If now began to inflate another bubble, bitcoin can surpass the previous ATH. But psychologically, it is difficult for me to invest at the current price!

On 9K there was no doubt, and now they have appeared!