Fidelity's digital asset custody expanded by $3.02 billion in the third quarter of 2025, according to recent data. The firm's holdings increased from $45.13 billion on July 1 to $48.15 billion by September 30. This growth was largely fueled by Ethereum, with Fidelity's Ethereum holdings rising from 625,770 ETH to 853,380 ETH, contributing nearly $1.97 billion in value. Conversely, Bitcoin custody balances at Fidelity decreased by 4,160 BTC during the same period. This trend indicates a shift in institutional interest towards Ethereum, as it gains traction over Bitcoin in Fidelity's portfolio.