The increase among all cryptocurrencies I believe came after the media boosted the "Greece crisis" to an extent where people feared their fiat currency was not safe. Not trying to undermine the problems of Greece, but it was overwhelmed to a degree. Bitcoin shot up quite nicely along with a few other altcoins.
Whales use fear and confusion all the time to their advantage. The only thing we can do is ride the waves. I should have bought LTC when I saw the Greece thing happening, it was clear they would pump it. Im sure for the next crisis LTC will go up too as well as BTC and some other random more risky to invest at alts.