Ever heard early birds catch the worm easily? That means being first improves the chance of success.[1]. It is a proverb which emphasizes the importance of starting something early to maximize potential income.[1] So I believe if anyone plans to invest in Bitcoin, the right moment is now especially when the market is still in the bear market sentiment. It is much better to invest during the bear market or idle moment than when the price is spiking. This way we are able to secure our profit much earlier. Of course, we always need to study the market and think rationally. Once we confirmed that it is ok to invest then invest right away and don't waste time waiting for another dip. There are lots of cases where many investors failed to invest at a much lower price because they keep on waiting for the price to crash.
It is always advised that we should invest the money that we can afford to lose.
[1] https://blogs.missouristate.edu/international/2020/09/29/learn-english-idioms-the-early-bird-gets-the-worm-meaning/#:~:text=Definition,to%20maximize%20the%20potential%20outcome.