A mystery Bitcoin whale just sent 1,000 BTC—worth $61 million at present—to Coinbase after first receiving the coins almost six years ago, on-chain data shows.

As tracked by Arkham Intelligence, the unidentified investor first received their coins in August 2018, when the stash was valued at just $6.68 million in total. Sending the coins to the exchange implies that they intends to finally sell, implying an 817% profit if they follow through.

The sale represents a long-standing pattern in crypto bull markets, where long-term holders begin dumping their coins as unrealized profits on their dormant BTC become too juicy to ignore.

Early last month, a separate Bitcoin whale dumped 687 BTC, valued at $43.8 million, after first receiving the coins on January 11, 2014—when Bitcoin traded at just $987 apiece.

More broadly, the long-term Bitcoin holder supply—that is, coins held for over five months at the same address—cratered from 16.2 million BTC in late December to 14.9 million BTC by late March. During that time, the asset’s price had soared from $40,000 to $70,000, implying that investors were finally cashing in.

Since then, the long-term holder supply has stayed mostly flat, as with Bitcoin’s price. Meanwhile, on-chain analysts have begun warning that this year’s Bitcoin bull market is losing its momentum, with whales cashing out $1.2 billion in profit during the first half of June.

Other large cohorts have been dumping too. Miners sold an unusually large amount of BTC early this month amid post-halving revenue setbacks. Furthermore, both the German and United States governments have been dumping hundreds of millions of dollars in BTC seized from criminals many years ago.

Bitcoin now trades for $60,775 per coin, down 11% this month. On Friday, the Federal Reserve is set to release the core Personal Consumption Expenditures (PCE) price index for May—its preferred inflation measure—which could affect market sentiment and inspire further volatility for the asset.

Edited by Andrew Hayward