I'm a bit confused how alt-coins values are based not just on their value, but on the value of Bitcoin or Ethereum. When ETH goes down, my alt-coin's, IOTA, value goes down . Now I am going on the final value, the value of the coin in FIAT. So the other day, IOTA went up some 3.xx% yet the value of the coin in fiat went down. . . I was confused, so I looked up the value of ETH, and it had dropped considerably (the big drop a few days back). . . I looked up the price of IOTA paired with BTC and the increase that IOTA saw when paired with ETH was not there, it was completely different.

So why does the value of a crypto such as IOTA, the value in fiat, why does it depend on the value of an unrelated token such as BTC and ETH??  I couldnt care less what the value of ETH is, I do not believe in that coin - so why does the final value of the coin I am interested  in depend so much on the value of ETH? What happens say in 5 years when IOTA is booming but say the value of ETH has crashed to nothing, as its coin is failure??? Does that mean the actual value of IOTA in fiat will also be nothing because ETH is worthless??

I dont understand that, why doesnt a coin stand on its own. I dont think the value of IOTA should depend on the value of ETH or BTC, thaT just doesnt make sense to me.