With LTC having a circulation that's 4x bitcoins circulation, it seems LTC is following bitcoin in market cap by one bullrun.
This means that when we compare the prices, during bullruns Litecoin will reach BTC/4 high from the previous bull run.
2017 bullrun BTC reached a high of ~20k usd, depending on the exchange. If history repeats itself that would mean LTC reaches 20/4 = 5k usd during this bullrun.
Buckle up.