Two mysterious Bitcoin (BTC) wallets holding a combined 1,000 Bitcoin — worth $61 million at current prices — have suddenly awoken after a 10-year hiatus, transferring out almost every single satoshi.

Wallet address “16vRq…qjzEa" transferred out its 500 Bitcoin at block 843,131 on May 12 at 7:10 pm UTC, while the other 500 Bitcoin was sent by address “1DUJuH…NgfC5” two blocks later, according to Blockchain.com’s Bitcoin block explorer.

The wallets each received 500 Bitcoin on Sept. 12 and Sept. 13, 2013, when Bitcoin was priced at $134, according to CoinGecko.

At current prices, the combined amount transferred is now worth 456 times more than their acquisition price, at $61.2 million.

Since the transfers, one of the receiving addresses from “16vRq…qjzEa” has already transferred the 500 Bitcoin onward to a multitude of , while the receiver from “1DUJuH…NgfC5” is still holding its 500 Bitcoin.

The proximity of the inward and outward transfers prompted blockchain analytics firm Lookonchain to pair the two transactions together, onlookers believe the two wallets were owned by the same person or entity.

Source: Lookonchain

Prior to the transfers, the two addresses were the equal 4,353rd largest Bitcoin whales, according to BitInfoCharts.

Less than a week ago, a Satoshi Nakamoto-era Bitcoin wallet transferred 687 Bitcoin, worth $43.9 million, to two separate addresses.

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While at least one of these early-day Bitcoin wallets tends to wake up each month, there are nearly 1.8 million Bitcoin addresses that have remained dormant for over a decade, according to a recent analysis by Chainalysis and Fortune.

These wallets, which exclude Nakamoto’s wallet, contain about $121 billion worth of Bitcoin, Fortune said.

While it is impossible to know how much this has been lost, the 1.8 million addresses account for 8.5% of the total 21 million Bitcoin that will ever exist.

People often speculate that dormant wallets may be waking up to sell Bitcoin at an opportune time,  others suggest it could be to transfer the funds to a different address, perhaps under a more secure noncustodial wallet service provider.

Bitcoin is currently priced at $61,450 and is up 130% over the last 12 months, according to CoinGecko.

Bitcoin’s change in price since April, 2013. Source: CoinGecko

Big Questions: How can Bitcoin payments stage a comeback?