We all know Bitcoin was bought to buy into altcoins. When the altcoin hype fades, so does demand for Bitcoin.
what you are saying about altcoin hype leading to bitcoin rise makes sense but i can't wrap my head around one thing.
lets assume your scenario was right.
people buy bitcoin with fiat and bitcoin price goes up.
they use that bitcoin to buy altcoins, so altcoins prices go up in alt/btc market.
then they stop doing that and take the bitcoin + profit and sell on btc/fiat market and price crashes.
this is what you are describing right?
but here is the thing. i see two types of altcoins, those on top which have both alt/btc and alt/fiat market and those small coins.
the small coins don't really get new money, it is a fixed amount of money that travels from one to the other and never exits other than from time to time the pumpers taking out the profit only. so i don't see this affecting bitcoin price that much.
about big altcoins if what you say is true, their prices in alt/btc market should drop because as we said people stopped using the BTC they bought in day 1 and now are selling that. but this is not happening!
for example LTC/BTC price has gone up about 10%
ripple went from 9K to 11K satoshi
NEM is still around 7700-8000 with little drop
ETC is still the same
Dash is still 0.066-0.067
ETH is probably the only one that dropped a bit.
in my opinion this shows the BTC has not left altcoin market for some reason it is the fiat that is exiting because all the altcoins i named are dropping hard in fiat value.
ETH -16%
XRP -13%
NEM -15%
LTC -6%
DASH -13%