If you bought $BTC with 1000u in January 2017, your return now is 90x. If you bought $BTC at 19000 in December 2017, your return now is 4x. A bull market is never the time to buy. Even if you wait until the next bull market to sell, your returns will still be pretty bad, and you'll be stuck for several years. 126000/69000=1.82609 126000×1.8=226800 Even if you buy back at 50000, the return after four years is only 300%.