My opinion, Bitcoin all time saving mode is the best way. Some time when bitcoin price up then sell and when price down then buy is the best decision. This method all time not working for trade. Many time i noticed when i sell bitcoin or altcoin sell since then price grow up and up. And when I buy bitcoin or altcoin then price low day by day. specialy, altcoin hold, sell and trade big loss. 4 years ago few coins i hold for future. now this coin price few value or most of coin value is zero. Few coin trade, there too big loss. the past year in the case of 1 coin investing $1000, this coin price today is zero.
There are two things I will list below that makes you experience this scenario,
1. Buying at the wrong time, though there is no best time for buying any crypto but buying in the less-risk zones or strong demand zones (intrinsic value) can save you.
2. Impatient: expecting the coin/crypto to start rising immediately after you hit the buy button, the market doesn't work that way, because the market has to turn, shake out and liquidate the weak hands before heading in its direction and if you are not a holder, Obviously you get shaken out by the short term price manipulation.