Bitcoin prices moved lower on Friday, but held within the short-term range that has the cryptocurrency on track for the quietest week since October 2018.

On Friday, a single bitcoin

BTCUSD, -0.60%

 was fetching $3,559.23, down 1% since Thursday at 5 p.m. Eastern time on the Kraken exchange. The best-known digital currency has traded inside the $3,425-$3,614 range on the week, the narrowest since beginning Oct. 22, 2018.

The slowdown in price activity has dragged the 3-month volatility index to 3.49%, its lowest level since Nov. 22, according to Buy Bitcoin Worldwide.

“We have seen a few sudden spikes but that’s mainly because volumes have tracked off. they are down about 20% from a week ago,” said Mati Greenspan, senior market analyst at eToro.

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Bitcoin volatility index

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Cryptocurrencies other than bitcoin — commonly referred to as altcoins — were trading lower on Friday. Ether

ETHUSD, -1.00%

 was down 1% at $115.32, Litecoin

LTCUSD, -0.77%

fell 0.9% to $32.11, Bitcoin Cash

BCHUSD, -1.79%

lost 2% to $125.70, and XRP

XRPUSD, -1.12%

was down 1.2% at 31 cents.

Bitcoin futures are tracking spot prices lower on Friday. The Cboe Global Markets February contract

XBTG9, -0.71%

was down 1% at $3,495, while the CME Group February contract

BTCG9, -0.28%

had lost 0.7% to $3,495.

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