Firstly, there is no such thing anyway. If 5 are invested in altcoins, at least 10 are invested in Bitcoin.
There is no such thing as well. How did you come with that conclusion, 5 and 10? That doesn't make any sense.
Secondly, let us assume that the situation has developed as you think, but this time the result will not be so. Because trader sells Bitcoin for getting altcoin.
They sell Bitcoin either go for flat or altcoins, sell Bitcoin just for solely getting altcoin is not a wise choice and shouldn't do that in the first place and also it's a bad run.