That’s hard to tell because nobody knows what the price of Bitcoin will be in future. Now, the price of Bitcoin is very low, so it is a good time to invest. But it is hard to tell when the price of Bitcoin will recover so invest if you can take the risk.
It is not hard for long term holders to know the right time to invest, only what is very hard about crypto is what is hard about stock and fiat, which is trading, asset crypto trading, investing is not hard but require patience. If the market had been very bullish, do not invest again, wait until the market is very bearish.
Like now, we know that the market is very bearish, we are in the bear market smtime, then why ain't we investing, this is the best time to invest. But more bearish market may come, never sell, or you may not even invest all your money for now so you can invest more during more bear market.
Investing is not as hard as some people may think, after bear market, bull market will begin, bull market may take months before it finally begins massively.