A bitcoin whale has moved a total of 88,857 BTC (worth over $1.1 billion) in two back-to-back transactions going from wallets associated with Xapo to unknown wallets, for a transaction fee totaling $3.54.

The transactions were spotted by Twitter-based large transaction monitor Whale Alert, which flagged them as coming from wallets associated with Xapo.

Xapo, it’s worth noting, is a bitcoin storage service that sold its custody business to Coinbase Custody last year. The large transactions could be the firm merely moving funds around to ensure they are securely stored in cold storage, or they could be part of an audit or security check.

Cryptocurrency exchanges and other businesses in the industry often store the majority of customers’ funds in cold storage, as holding them offline ensures the funds are protected against hackers. Xapo itself is known for having used a network of underground vaults, which span across five continents, including one in a decommissioned military bunker.

In May 2018, CryptoGlobe reported that Xapo held about 7% of bitcoin’s circulating supply in cold storage vaults, equal to around $10 billion at the time. Xapo’s chief executive officer Wences Casares spent years pitching the firm and the cryptocurrency to Silicon Valley millionaires and billionaires.

The large transactions come at a time in which the number of bitcoin whales – clusters of addresses holding over 1,000 BTC combined that belong to a single entity – hit a four-year of 1,939. The rise came after the price of bitcoin surpassed the $13,000 mark on news that PayPal will start letting its users buy, sell, and hold cryptocurrencies through their platform.

Featured image via Pixabay.