The rapid accumulation led to speculation it could be a new entity buying bitcoin, especially amid a flurry of spot bitcoin exchange-traded fund (ETF) filings in the U.S.
On-chain analytics firm CryptoQuant told CoinDesk in a Thursday note that the address, bc1qchctnvmdva5z9vrpxkkxck64v7nmzdtyxsrq64, was a new one for the BitMEX exchange's cold wallet, or a type of custody that isn't connected to the internet.
A 566 BTC transfer was the biggest single transfer. The address appears on BitMEX's latest proof-of-reserves holdings published on Nov. 28. CryptoQuant has previously labeled the sending addresses as belonging to BitMEX.
“This new address received the Bitcoin from a total of 450 addresses,” CryptoQuant said. “These addresses also appear on BitMEX's Proof-of-Reserves report and have the characteristic bc1qmex prefix.”
BitMEX was probably conducting an internal transfer because it is migrating most of its bitcoin holdings from the 3BMEX format to addresses with format bc1qmex, the firm said. There are also Bitcoin addresses that start with “bc1q” that support SegWit, a type of bitcoin transaction, natively, allowing more efficient transactions that can pay lower fees.
As of Thursday, the wallet was the 74th largest holder of bitcoin, according to Bitinfocharts.