Hmmm, for me that best time to make a comeback is during crypto's pullback because the price is so cheap. Just look at bitcoin today, almost touching 5 digits again and the last lower lows was like $3k. So if you have invested that time then its already 3x by just holding.

Altcoin market is also recovering, might be a good time to join the bandwagon again early 2020 because once the market had recovered and go on a full blown bull run, regrets!!.