Does LTC price correlates to BTC price? I always expected the LTC and BTC exchange rate to show synchronous tops/bottoms, but to my surprise LTC seems to remains stable during BTC crashes (and vice versa).

Is this because I'm a novice at chart-analysis, or is there really little correlation?
Assuming that the BTC price is falling against USD, either BTC/LTC will remain stable and LTC will crash proportionately against USD or LTC/USD will remain stable and BTC will crash against LTC or something in between.  Otherwise, there will be arbitrage opportunities by changing by using LTC as an intermediary between BTC and USD