Ethereum share price has fallen against Bitcoin: is it the fault of waiting for Shanghai?

Today is the day of the long-awaited Shanghai update of Ethereum: perhaps this is already having a negative impact on the price of ETH, as it has fallen more than Bitcoin.
Yesterday the price of Ethereum held almost steadily above the $1,900 mark, but fell below that threshold in the evening, and overnight fell to just above $1,860.
In other words, it lost 3% that very night before the Shanghai update was supposed to be realized, even though it would have been expected overnight at that time.
That this -3% is not just due to external factors is shown by comparing it to the BTC.
In fact, the price of BTC fell only to $29,900 overnight from yesterday's $30,200, that is less than 1%, which makes it clear that the cryptocurrency market does not look so troubled at the moment to justify a 3% drop in price.
For example, Solana is +2% today and Polkadot -1.5%, although many of the major altcoins are following Ethereum's 3% drop.
So it is not the cryptocurrency markets as a whole that are losing 3% today, but it is the price of ETH that is causing such losses for many altcoins.
Even more illustrative in this regard is the ratio of BTC to ETH market capitalization.
While it was down to 2.37 on April 5, it has now risen to 2.58, which is the highest since July 16, 2022.
Moreover, on April 3 it was already higher than 2.5, so in fact the growth of ETH price due to the Shanghai Ethereum update lasted just three days.