$100k was everyone's target for bitcoin so I think most of the investors who were already holding bitcoins sold once the price of bitcoin crossed $100k. And everyone is looking forward to the next bear season. We know that bear season will come again for Bitcoin and all other coins so it is better to wait for it than to panic and invest again in this bull season. In case of futures trading you can take entry both long and short so it is also not a bad option but you must always trade with low leverage for fund safety.
If you bought early yes but for those who just bought recently, $100k is still nothing for them as their profit is still low. Old buyers might still save some just in case the bull continues, so both types of investors can still look forward for it. Yes, there will always be a bear market apart from the bull run, as both of them are part of how this crypto market works. It is just that we don't know the exact time if when they will occur.
There are signs but sometimes they are inaccurate, this is why some people can make mistakes. As for the futures trading, there might be a proper entry for it depending on what is the current market but yeah, it is always best to be safe and go with lower risks than sorry.