Dollar Reserve Share Decline Driven by Portfolio Adjustments and Reserve Size Changes
On September 2, 2026, the Federal Reserve Bank of New York released a study analyzing changes in global official foreign exchange reserves. The report highlights that the share of the US dollar in these reserves decreased from 64% at the end of 2015 to 56% by the end of 2025. This reduction is attributed not only to shifts in currency preferences by central banks but also to changes in the total size of reserve holdings. In some cases, countries increased their reserve amounts but allocated a smaller portion to dollar assets, dragging down the overall global dollar share.
The research team—Linda S. Goldberg, Oliver Hannaoui, and Sneha Parthasarathy—utilized IMF COFER data to illustrate this phenomenon. For instance, Switzerland’s total foreign exchange reserves grew between 2015 and 2019, which led to a lower overall dollar share, despite Switzerland itself increasing its direct dollar allocations. These structural patterns emphasize that a drop in the global dollar share does not necessarily mean central banks are divesting from dollar holdings.
Reserve Data From Multiple Nations Reveal Detailed Drivers of Change
Examining data from 79 countries between 2015 and 2019, with complete information for 76, the report quantifies contributions to the dollar share decline: currency preference shifts accounted for a 1.2 percentage point decrease, while reserve size changes contributed a 1.5 percentage point drop. In the subsequent 2019–2023 period, among 62 countries with full data, preference shifts slightly increased the dollar share (+0.3 points), but reserve size effects pulled it down (-0.5 points).
Notably, the study acknowledges missing 2023 dollar allocation data for major economies including China, Russia, Mexico, and Morocco. When modeling these gaps, the researchers estimate their aggregate preference shift contribution at around negative 2.0 percentage points, aligning with the global 2.3 percentage point decline in the dollar share. This underlines ongoing uncertainties due to incomplete public data from key reserve holders.
Reserve Diversification Does Not Confirm Bitcoin Adoption by Central Banks
A March 2024 follow-up New York Fed report (No.1087) differentiates between reserves held for liquidity purposes—such as trade settlements, foreign debt servicing, and currency stabilization—and those held for investment diversification. By applying liquidity metrics like short-term external debt and three-month import cover, the report concludes that diversification beyond these needs does not necessarily signal central banks' investment in cryptocurrencies like Bitcoin.
Covering reserve portfolio evolution from 1999 through 2023, the analysis found no documented cases of central banks officially incorporating Bitcoin into their reserves. A noteworthy exception is the Czech National Bank’s November 13, 2025 announcement of a $1 million digital asset test portfolio, which includes Bitcoin, USD stablecoins, and tokenized deposits. However, this experimental fund is excluded from official reserves, highlighting a cautious approach to digital asset exposure rather than formal reserve adoption.
Summary: No Definitive Evidence of Central Banks Buying Bitcoin Amid Dollar Share Decline
The New York Fed’s findings make clear that the decline in the US dollar’s global reserve share is influenced by complex structural factors rather than a direct movement of central banks into Bitcoin. Confirming sovereign demand for Bitcoin would require transparent disclosures detailing asset allocations, funding sources, and transaction records, along with clear distinctions between official reserve holdings and other investments.
As such, market interpretations linking the shrinking dollar reserve share to central bank Bitcoin purchases remain speculative without further data. Continued transparency and reporting will be vital to verify any emerging trends in official reserve diversification involving cryptocurrencies.