Litecoin is going up because some exchanges added LTC pairs and people moved from trading against BTC to trading against LTC due to lower network fees.
People don't need to convert first from LTC to BTC and then to FIAT, because sites like Coinbase convert straight from LTC to FIAT.
Which exchanges?
I haven't checked all the exchanges, but for example TradeOgre has more volume on LTC pair for some coins than on BTC pair. C-Patex is one of the exchanges that accept LTC as listing fee instead of BTC.