If you "mine and HODL" ETH for 24 hours, you'd get $17 in ETH and it would be worth $34 next year.
If you "mine and HODL" ZCASH for 24 hours, you'd get $20 in ZCASH and it would be worth $25 next year.

HOWEVER, if you MINE ZCASH for 24 hours and convert it to ETH, then you'd end up with $40 next year.