In terms of price, BTC is king.

If BTC falls slow, LTC falls quicker and recovers quicker, so bigger swings.  LTC's cap the past 3-4 years has been .02 btc, and good buys are at .01 btc.  LTC has been above this in it's first few years but not since.  ETH can shrug off a slow fall from BTC, and ETH's btc ratio will climb.  The investor circle is not as connected between these two.

If BTC falls fast, LTC will fall faster as well as ETH, and both will recover twice as fast as BTC on high momentum falls.

If BTC stays stagnant, and LTC is near .02 btc it will be stagnant, if lower it will jump after 1-2 days of stagnation.  During BTC being stagnant, ETH will typically rise within 1/2-1 day.

If BTC slowly rises, ETH and LTC will slowly rise with it.

If BTC rises fast, ETH and LTC will rise half as fast so their BTC ratios will fall, due to funds shifting out of ETH and LTC and into BTC.

So the best market for ETH and LTC are BTC stagnation after a rise, and recovery from a fall.