USD/BTC price vs other altcoins

[cryptotrader12345]

Hi!

Can someone explain me why on www.coinmarketcap.com when you compare the price of the altcoin tot the USD and BTC the price increase to the USD is always much higher and more upwards than versus the BTC.

I don't understand how this is possible.

When you compare the price of the altcoin vs the USD there are sometimes X 10 increases and when you compare the price of the altcoin to the BTC you only get an increase of for example by only X 3.

How come?

TIA