Most people believe that the price of altcoins' is determined by the price of bitcoin and that they tend to follow it's market movements.
There are 4 school of thoughts here:
[1] Bitcoin goes up, Altcoins goes down
[2] Altcoins goes up, Bitcoin goes down
[3] Both market goes on a bullish trend
[4] Both market suffered, massive downtrend
I partially disagree with this. I have studied prices of coins and tokens on CMC and the fluctuations of each currency seems to be unique and independent of any other digital currency. Some show strong pumps when BTC goes down and some heavy dumps when BTC is rising.
Just look at my post above. I wouldn't save that bitcoin control the market, but it has influence the crypto market because its the dominant coin.
Undoubtedly, there are market forces and factors which affects most currencies, this is not influenced by bitcoins price, it rather controls bitcoins' price as well as others.
So when trading or investing, make sure you treat each currency differently as they have different utilities.
This is a free market, no one has total control. If you are talking about the whales, yes, they could one factors but you have to see the total picture, there are a lot of players around and then the Universal Economic Theory - Supply and Demand, which is very applicable to this market.