I think you need to look at the last few months value.

coins that were 0.10 in Dec, jumped to $1 / $2 they are now dropping back  down  *towards*to  mid December  levels.  I would take this as a bottom  value. Any coins that have got close to that +% are probably worth investing in. Those that are still way above Decemeber I think still have some way to fall.

Late December / early Jan was a crazy period and many people got carried away (raises hand lol) thinking those gains were permanently when history would have showed they weren't.

But the ride isn't over yet, still good profits to come in 2018