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I agree with Xavofat that usually(not 100% of the time) other altcoins do rise together with bitcoin. Looking at the charts comparing Bitcoin to Ethereum itself won't be accurate enough as there are alot of altcoins out there that has decent economy; Ethereum just really went down, and I think it's really not related to bitcoin's rise in price. Take a look at the other alts that rose together with bitcoin (e.g. NEO, IOTA, STEEM).
Though I can be wrong, feel free to correct me aswell.
ethereum was just an example, you know making each one of those charts took some time from me, they are not just available on the internet for me to go and take a screenshot to share here!
I have to go extract the data for price on each dates for bitcoin and each altcoin (twice: 1 for their BTC value and 1 for their USD value) and then type them in excel and draw the charts in a way to show the lines like that (with 2 sets of data on different scales).
I may do it for a couple of other altcoins later if I can manage to get some free time, but from my experience those 2 charts above are a good representative of what I have been seeing so far.
obviously there are exceptions such as NEO to this rule and there is a good explanation for it too. NEO changed its name and had a very nice pump and hype recently and that is an exception.