A dormant Ethereum wallet containing $15 million activated after eight years and transferred its funds to another address.

The wallet first made a test transaction with 1 ether ($1,845) before sending the remaining 7,999 ether to the address, as noticed by on-chain analysts Lookonchain.

When the owner participated in the Ethereum ICO, or initial coin offering, the funds were purchased for around $0.31 per token, or just shy of $2,500 in total. That means the owner is sitting on a 591,900% return on investment at current prices.

The funds have been moved to another wallet with limited transaction history. The only other movement in that wallet is a 207 ether ($380,000) inbound transaction that was made only a few minutes earlier. These funds were sent from a different wallet that hadn’t been active since 2017.

It’s unclear why this Ethereum ICO participant is consolidating some — or all — of their funds into one wallet. They don’t appear to have been sent to an exchange and haven’t been sold on-chain.

These types of movements have happened a few times in the past. In December, two addresses moved $27 million of ether, of which some funds were from the Ethereum ICO. In April, another ICO participant moved $4.4 million of funds.