This chart depicts the dominance of Bitcoin and Ethereum. Dominance means their market cap relative to the entire crypto market cap. This chart tracks the gains and losses in % since the startof the year. As you can see Bitcoin started out great, but then ran into some trouble and ETH took over. Now they are consolidating and at the time of writing it looks like BTC.d is trying to push up and ETH.d is stalled a bit.
Orange line = ETH
Blue line = BTC