Arthur Hayes, BitMEX co-founder and crypto macro investor, argued on August 11, 2026, that a coordinated U.S.-Japan effort to strengthen the Japanese yen could ultimately inject more dollars into global markets — creating a major liquidity catalyst for Bitcoin and other crypto assets.

Hayes's analysis follows a joint U.S.-Japan currency intervention earlier in August aimed at the dollar-yen exchange rate. The yen's persistent weakness stems in large part from a wide interest-rate differential: while the Federal Reserve held rates elevated, the Bank of Japan maintained ultra-low rates, encouraging capital outflows from Japan and pressuring the currency.

Yen Drops to a 40-Year Low

In late July, the yen fell past 163 to the dollar, reaching its weakest level in approximately four decades and driving up the cost of imported goods for Japanese consumers.

On August 1, the U.S. Treasury and Japan purchased yen to support the currency — the first such joint intervention in over a decade — pushing the dollar down to roughly 156 yen.

In an essay titled "Yen-quake," published on his Substack, Hayes argues that the next logical step could be an expanded FIMA facility, a move he says could carry significant implications for Bitcoin.

Hayes Identifies FIMA as the Most Viable Path

Hayes outlined three possible routes to a stronger yen: an aggressive Bank of Japan rate hike, asset sales by Japan's Government Pension Investment Fund (GPIF), and use of the Federal Reserve's FIMA repo facility.

FIMA — the Foreign and International Monetary Authorities repo facility — was introduced by the Fed in March 2020 to supply dollar liquidity to foreign central banks during the pandemic-induced market stress. It enables those institutions to temporarily exchange their U.S. Treasury holdings for dollars without selling those bonds outright.

Hayes contends that the first two options carry political and economic costs that render them unrealistic, leaving FIMA as the most viable mechanism.

Under this scenario, Japan's Ministry of Finance would pledge U.S. Treasury holdings as collateral to the Fed, borrowing dollars without selling the bonds. The Treasury would then sell those dollars for yen and reinvest in domestic bonds and equities. Hayes said this approach expands the Fed's balance sheet while avoiding disruption to the Treasury market.

Hayes pointed to Treasury Secretary Scott Bessent's public calls for the Fed to raise the FIMA facility's $60 billion per-counterparty cap as evidence the plan is advancing. Bessent's remarks came days after the joint U.S.-Japan currency intervention. Any increase to that cap would require approval from the Fed's Foreign Currency Subcommittee, which operates under the FOMC.

Hayes estimated that Japan and the GPIF together hold $1.373 trillion in U.S. Treasuries eligible as FIMA collateral.

Why Bitcoin and Crypto Could Benefit

Hayes links his thesis directly to Bitcoin, arguing that additional dollar liquidity would increase demand for financial assets, with Bitcoin among those most likely to benefit. The premise echoes a pattern observed during 2020–2021, when Fed balance sheet expansion coincided with significant appreciation across risk assets including Bitcoin, though past correlations do not guarantee future outcomes.

He also highlighted Ethereum (ETH) as a large-cap sleeper candidate. ETH failed to eclipse its all-time high in 2025 and remains the foundational security layer for Real-World Assets (RWAs).

Additionally, he flagged Ethena (ENA), down more than 90% from its peak, as a candidate for a 5x to 10x gain if stronger dollar liquidity boosts Bitcoin and increases yields on Ethena's USDe stablecoin.

Broader Implications

If the Fed expands the FIMA facility to support Japan's yen defense, the resulting dollar liquidity could boost demand for Bitcoin and other crypto assets, according to Hayes's framework.