Historically what happens to a coins price when asics come online?

[panningforcoin]

This question is for you ole timers with a wealth of experience.
What generally happens to a coins price when asic's come online for the coins algorithm?
I'm speculating about zcash and zencash since the Bitmain Z9 Mini & Innosilicon A9 Asic miners are now mining Equihash.
Will zcash and zencash go up or down in price in the near future based on historical evidence of other coins response when Asic's first hit their algorithm?

Thanks!