I was thinking about this, so how does this go? BTC goes up, everything else goes down.
Because the exchange rate CGB/BTC is based on BTC. Just look at it using numbers: 1/10 , 1/100 , 1/1000 = .1 , .01 , .001
You can see as the denominator (bottom number) increases from 10 to 100 to 1000, the overall number gets smaller.
But the dollar amount is still looking good:
http://coinmarketcap.com/Then BTC crashes and everything else goes up and then BTC goes up again in a more sensible way?
Yeah, because strong holders take up the supply so that the next leg up has less selling pressure.