Bitcoin's price extended its recent decline late Thursday, falling for the seventh day in nine, to as low as $50,450.

The largest cryptocurrency was changing hands around $51,800 as of 21:23 coordinated universal time (5:23 p.m. ET).

Bitcoin (BTC) is down 9.8% since Sunday, the biggest drop on the weekly price charts since late February.

A recent rally in prices for ether (ETH) and other alternative cryptocurrencies has coincided with a stalling out in bitcoin's rally this year.

Earlier Thursday, bitcoin's so-called dominance ratio – its market capitalization as a share of that for all cryptocurrencies – slipped below 50% for the first time since 2018.

Bitcoin also has broken below its 50-day moving price average on the daily chart, seen as a sign of slowing momentum.

Pankaj Balani, CEO of crypto derivatives venue Delta Exchange, told CoinDesk earlier Thursday the outlook was starting to look bearish for bitcoin.

“BTC has slipped below the 50-day moving average support that it held sacrosanct through this rally, and looks like there is more downside here,” Balani said.