The price of ether (ETH) tumbled suddenly in cryptocurrency markets Thursday, ending a stretch of price stability that prevailed in the hours after the Ethereum blockchain completed its historic shift to a more energy-efficient proof-of-stake blockchain, CoinDesk reports.

The second-largest cryptocurrency by market value was down 9.1% to $1,489, its biggest daily decline since Aug. 26. By contrast, bitcoin (BTC), the largest cryptocurrency, was down only about 2% on the day.

The sudden price dump looks like a "buy-the-rumor, sell-the-fact" response, said Riyad Carey, a research analyst at crypto data firm Kaiko.

There is still a lot of leverage in ETH markets, so volatility should be expected and will probably be welcomed by traders who watched the Merge go by without much of a move up or down,” Carey told CoinDesk in a written note. “We’ve also seen market depth decrease and spreads increase, so that will likely factor into larger price movements.