One more thing to consider.

Bitcoin halved to 12.5 bitcoins per 10 minutes in June 2016.

Litecoin is still at 25 per 2.5 minutes currently (100 litecoins per 10 minutes), so Litecoin flows are at 8:1 to Bitcoin flows currently.

Litecoin block reward halves in 2 years (18th August 2019) to 12.5 per 2.5 minutes, and Bitcoin halves again to 6.25 bitcoins every 10 minutes in June 2020.

Litecoin to bitcoin flows will narrow to 4:1 for 1 year (2019) before widening again to 8:1 (2020).

Bullish Litecoin in 2019, and Bitcoin in 2020.