Etherum reached $4k when bitcoin price recorded a new ATH in January. However, I don't think that Etherum will be able to reach that amount when bitcoin price will make a new ATH because the price of Etherum doesn't show any significant uptrend so far. Don't be surprised that the price of Etherum might dip below $1500, if the bear market arrives.
Yes, because the price drop that occurred in ETH at that time, when BTC also dropped, was very drastic, even exceeding what happened to Bitcoins and several other top altcoins. Even down below $1.5k, right at that time? So, when the ETH price increase performance is so rapid, the price will still be quite difficult to follow the movement of Bitcoin which is indeed very impressive.
For now, the price of ETH has only reached $1.8k when the price of BTC has risen to $97k. So, ETH really needs a real and skyrocket high pump so that it can really boost its price maybe up to more than $2.5k.