Bitcoin vs alts price action

I still cannot wrap my head around this concept:

If Bitcoin goes up alts go down
If Bitcoin goes down alts go down
If Bitcoin goes sideways alts go up

What is the reason for this? They are traded against each other, so if one goes up the other one should go down?

Yes its straight forward that when Bitcoin goes up in value alts are worth less and therefore ' go down '
But the opposite is not true for some reason.

Note: this has nothing to do with the market crash which is going on at the moment, I am talking in a general perspective in ' normal days '

There is no singular reason. It comes down to multiple variables, including

• available trading pairs for altcoins
• lack of direct currency -> altcoin buy options at exchanges
• too many moving parts for newbies to want to deal with buying altcoins
• bitcoin is the most volatile in price, making extremely quick gains possible for day traders.

waterworks said:

There is no singular reason. It comes down to multiple variables, including

• available trading pairs for altcoins
• lack of direct currency -> altcoin buy options at exchanges
• too many moving parts for newbies to want to deal with buying altcoins

Click to expand...

Do you mind going in on these points?
1) What do other trading pairs have to do with BTC vs X altcoin. I dont see how ETH/NEO affects BTC/NEO with regard to what I said about if one goes up and the other goes down
2) Again a lack of direct currency doesnt affect BTC vs X altcoin. You have to see this as a separate thing
3) ?

Bitcoin is the alpha dog and alts are the puppies playing in his yard. The only safe time to play in his yard is when the big dog is happy (horizontal price). When the big dog is hungry (price goes up) the little puppies get eaten and when the big dog is angry (price goes down) then the little puppies could get bitten, therefore it’s time to get out of his yard!