A positive feedback loop with Coinbase / GDAX and its huge customer base I'd guess. Throw in that both BTC and ETH are having scaling problems and it looks to the noobs that Litecoin is the only crypto that works.
To top things off the /r/Litecoin subreddit subscribers increased over 8% with 8000+ new subscribers yesterday which is greater than /r/BTC has every achieved.

Imagine what would happen to Monero's price if it was thrown in the face of that many people.