trading eth/btc, you're basically tracking how ETH stacks up against Bitcoin. it's pair digital currencies, so similar stuff tends to affect them. Like certain news, hacking exchange or trends might push them both up or down at the same time. On the other hand, if you're looking at eth/usd you're comparing ethereum to real-world cash like US dollar. Stuff that messes with the dollar, like decisions from the US Federal Reserve (Feed), could shake up this pairing. But, what really matters ain't just about which pair you pick, but how you make close for profits. Don't problem if you has little profits, you just need time and experience for that.