It was a big day for spot bitcoin ETFs, and BlackRock appears to be the victor in the first day of trading.

On a day in which spot bitcoin ETF trading volumes reached nearly $4.6 billion, BlackRock's fund saw just over $1 billion, according to data from Yahoo Finance compiled by The Block. That made BlackRock's instrument the top-performer in terms of volume among new bitcoin funds.

Fidelity ranked as the second-best performing ETF among the new crypto-based funds, racking up $685 million in trading.

"While it's premature to make final judgments, this significant trading volume indicates a considerable influx of investor funds into the spot-based bitcoin ETFs," said James Butterfill, head of research at CoinShares.

First day of trading

Thursday marked the first day of trading of spot …