Fidelity’s digital asset custody expanded by just over $3 billion in the third quarter of 2025, rising from $45.13 billion on July 1 to $48.15 billion by September 30, according to data retrieved by Finbold research.
Finbold extracted on-chain ETF holdings data for the Fidelity Wise Origin Bitcoin Fund (FBTC) and the Fidelity Ethereum Fund (FETH), comparing snapshots from July 1 and September 30 to track changes in assets under custody. The resulting analysis highlights Ethereum as the primary driver of growth, reflecting the continued institutional embrace of smart contract platforms.
Notably, the firm’s ETH holdings jumped from 625,770 ETH to 853,380 ETH, with the additional 227,600 tokens translating into nearly $1.97 billion in added value as prices rallied from $2,502 to $4,139.
Interestingly, the scale of that expansion contrasts with Bitcoin, where custody balances slipped by roughly 4,160 BTC, even as prices advanced from $108,383 to $112,162. The divergence suggests that Fidelity’s clients were rotating toward Ethereum exposure during the quarter, reflecting a shifting institutional narrative beyond Bitcoin dominance.
The Q3 uptick followed a mixed first half of the year. In the second quarter, Fidelity recorded strong growth as its portfolio expanded by $11.05 billion, rising from $33.61 billion at the end of March to $44.66 billion on June 30.
Ethereum was again the standout driver of expansion, with balances increasing by 131,560 ETH as prices advanced from $1,829 to $2,437, lifting ETH’s dollar value from $904 million to $1.52 billion. Bitcoin also contributed materially, adding $10.43 billion as its price jumped from $82,697 to $107,333, though ETH’s percentage gains were far stronger.
By contrast, the first quarter had been negative, with Fidelity’s assets falling by $5 billion as prices slumped and holdings were pared back, shrinking from $38.61 billion on January 1 to $33.61 billion on March 31. ETH was hit especially hard during this period, with balances dropping by 156,000 tokens and valuations collapsing by nearly 60%.
Year-to-date, the firm has still managed to add around $9.54 billion to its custody business, even with the Q1 setback. Ethereum has emerged as the key contributor to this rebound, with Fidelity’s ETH reserves climbing by more than 350,000 ETH since March.
The scale of the difference was also evident over the third quarter as a whole. BlackRock’s portfolio expanded by $22.46 billion between July and September, rising from $79.63 billion to $102.09 billion. Fidelity’s $3.02 billion increase, while notable, represents less than one-seventh of that figure. Both firms, however, leaned heavily into Ethereum during the quarter, underscoring the growing institutional appetite for smart contract platforms alongside Bitcoin.
Despite the gap, Fidelity’s steady progress highlights that it remains a meaningful player in institutional crypto custody. Its continued expansion in Ethereum in particular reflects how large asset managers are diversifying exposure beyond Bitcoin, a trend that has accelerated throughout 2025.
