Key Takeaways
- Arthur Hayes published his “Yen-quake” essay on Substack on August 10.
- Japan and the GPIF pension fund hold a combined $1.373 trillion in U.S. Treasuries as leverage.
- The Fed’s FIMA repo facility caps each counterparty at $60 billion, a limit Hayes expects to rise.
Three Ways to Strengthen the Yen
Hayes, the BitMEX co-founder and macro commentator, laid out his thesis in an essay titled “Yen-quake,” where he argued the dollar-yen exchange rate has become a political problem for both Washington and Tokyo. He identified three mechanisms by which the two governments could push the yen back up, namely:
- Aggressive interest rate hikes from the Bank of Japan
- A shift by Japan’s Government Pension Investment Fund (GPIF) away from overseas assets and toward domestic holdings, or Japan’s Ministry of Finance pledging U.S. Treasuries to the Federal Reserve in exchange for dollars, then selling those dollars to buy yen
- Tapping the Fed’s Foreign and International Monetary Authorities (FIMA) repo facility (a scenario Washington and Tokyo currently favor), thus strengthening the yen without forcing Japan to dump its Treasury holdings on the open market
The third move, Hayes believes, could spike U.S. bond yields.
The FIMA Repo Mechanism, Explained
The FIMA facility lets foreign central banks temporarily exchange their U.S. Treasury holdings for dollars through the Federal Reserve, rather than selling those Treasuries outright. Japan’s government holds roughly $1.143 trillion in U.S. Treasuries, and the GPIF holds another $230 billion, for a combined $1.373 trillion in collateral, Hayes says could theoretically be pledged through the facility.
The catch is the FIMA facility’s per-counterparty cap, currently set at $60 billion. Hayes points to recent comments from Treasury Secretary Scott Bessent about expanding FIMA repo limits as evidence the ceiling could rise, which would let Japan pull far more dollars out of the facility than is currently possible.
Hayes also cited a recent coordinated foreign-exchange intervention, in which the U.S. and Japan reportedly spent a combined $100 billion attempting to manage the exchange rate, as a sign policymakers are already moving in this direction. He postured the setup as a modern echo of the “Plaza Accord” era, when coordinated intervention last reshaped the dollar-yen relationship, though he stopped short of predicting exactly when a formal agreement might be announced.
Why This Matters for Bitcoin
Hayes’ argument centers on the fact that expansions of dollar liquidity, however they are engineered, tend to lift bitcoin and other risk assets. If the Fed’s balance sheet grows to accommodate more FIMA repo activity, Hayes contends that liquidity does not stay contained to foreign-exchange markets. It leaks into global asset prices, bitcoin included.
Bitcoin.com News has previously covered Hayes making a related case that Fed rate cuts, even those triggered by unrelated geopolitical shocks, tend to be bullish setups for bitcoin once the initial volatility clears.
That said, not everyone in Hayes’ orbit takes his macro calls as certainties, given his track record on precise timing has been mixed. Even his latest essay itself acknowledges that yen intervention is a political decision as much as an economic one, subject to delay or reversal if Tokyo or Washington’s priorities shift.

