Many people think that effect on price must take a place right after the halving, but that's not accurate statement. For BTC it took over a year after the halving to make a significant price action. Fir Litecoin, you can see a continuous downtrend after the BTC halving, until Bitcoin reached new ATH. I have formed it in the first big Elliott Wave while BTC reached ~1800$ price target in 2017, that was the time when LTC started its uptrend.