Onchain activity continues to support the bullish case in bitcoin.

On Wednesday, just over 28,000 BTC worth $1.19 billion left centralized exchanges, the largest single-day outflow in BTC terms since Dec. 14, 2022, according to data tracked by blockchain analytics firm Glassnode.

Net outflows from exchanges are often taken to represent investors' intention to take direct custody of coins or preference for a long-term holding strategy.

The Nasdaq-listed Coinbase, which is the custodian for nine of the 12 proposed spot BTC exchange-traded funds (ETFs) in the U.S., alone saw an outflow of over 18,000 BTC on Wednesday, per analytics firm CryptoQuant. That has the crypto community on social media platform X speculating about institutional activity ahead of an expected ETF launch in early January.

The overall BTC balance in wallets tied to centralized exchanges has dropped to 2,327,025 BTC, the lowest since April 2018. Other things being equal, fewer coins on an exchange mean weakening supply-side pressures and potential for price appreciation.

Bitcoin changed hands at $42,700 at press time, up 158% on a year-to-date basis, CoinDesk data show.