There is definitely a relationship between the price of bitcoin and altcoins. Altcoins drop as bitcoin moves harder. In fact, whether the bitcoin rises or falls, the first reaction of altcoins is falling. After Bitcoin is fixed and stays stable, altcoins start to increase.
so altcoin movement actually so funny, its need unique condition to move follow bitcoin price. when traders thinking bitcoin price will rose , altcoin dumped and when bitcoin dumped its dumped too. so its definitely make confuse when we have to strart buying altcoin. only market psychology and confidence will make cryptocurrency move in one direction. trustness that bitcoin already totally recovered will support it..
Altcoin market movement is funny as you said because it is high manipulated but theres currently no connection between Bitcoin and Altcoin market and the only altcoin that seems to correlate with Bitcoin price is ETH sometime it also dont either.
With that been said, it will be time when Bitcoin market is total stable in terms of bullish market before altcoin market can totally correlate with Bitcoin.