Japan’s central bank has decided to sell its stock funds about 2.6 times faster than usual, reducing the estimated time needed to dispose of them from 112 years to 43.

If you’re wondering why such a supercharged exit still stretches across more than four decades, it’s because the Bank of Japan is trying to undo years and years of purchases without disrupting the market it helped support.

Those numbers come from the BOJ’s own calculation, which divides its end-September holdings by annual sales. They show just how long a monetary-policy experiment can outlast the decision to end it.

On Oct. 30, the bank held its overnight interest-rate target around 1.25% while approving faster ETF disposals from January 2027. The rate decision governs the current cost of money, and the sales program deals with assets accumulated under an earlier effort to make investors more willing to take risks.

Private buyers now have to accept more of that equity exposure, at prices the BOJ is prepared to accept.

How the Bank of Japan ended up owning stock funds

The BOJ brought equity funds into its monetary easing program in 2010, when the bank wanted to encourage investment in an economy struggling with weak demand and deflation.

By buying exchange-traded funds, which hold baskets of company shares, the bank could gain broad stock market exposure rather than pick individual companies to invest in.

At the time, its stated objective was to reduce the extra return investors demanded for holding risky assets. When a central bank adds demand for equities, it can support their prices and encourage investors to accept lower prospective returns for owning them.

That was a way to ease financial conditions when short-term interest rates were already near zero.

Even at the outset, the bank acknowledged the consequences of moving into these assets. In a November 2010 explanation of the program, then-Governor Masaaki Shirakawa discussed potential losses and the effects of the central bank’s deeper involvement in allocating resources across companies and industries.

That kind of ownership brought responsibilities that would continue beyond the purchases themselves.

The bank ended new ETF purchases in March 2024, but stopping purchases left the existing investments on its balance sheet. Unlike an individual bond, an ordinary equity ETF has no maturity date when the issuer repays principal, so the BOJ couldn’t just stop reinvesting and wait for the portfolio to expire.

To exit this trade, the bank needs to transact with actual buyers, who assume the risk of future gains and losses.

ETF units can pass between investors without selling every underlying share immediately, but the central bank still needs demand for the investment it wants to relinquish. It would be much easier to announce an end to support than to find acceptable prices for the accumulated holdings.

That explains the restraint in its disposal rules, which require seeking “appropriate prices” and want to avoid both losses and disruptions to the market in Japan as far as possible.

Selling faster transfers risk sooner but asks buyers to absorb more each year. Selling slowly leaves the bank exposed to equities longer. ETF sales began in January 2026 and have now accelerated, while retaining the option to adjust or suspend disposals when market conditions warrant it.

Selling faster without selling in a hurry

The new pace is about ¥860 billion annually at book value, up from ¥330 billion. Book value is the accounting amount assigned to the holdings being removed, rather than the cash the BOJ expects to receive. However, the difference between these values can be huge.

Using the relationship between market prices and book values in ETFs it sold during January through September, the bank estimates that the new pace corresponds to about ¥2.46 trillion at market value.

The market value equivalent can also move as prices move, while the book value pace defines how much of the recorded portfolio is being sold.

Source: Bank of Japan, Oct. 30, 2026. Disposal horizons assume a constant book-value sales pace; they are arithmetic estimates, not completion forecasts.

The bank estimates that its revised sales will represent roughly one-thousandth of market trading value, based on activity in the Tokyo Stock Exchange’s Prime Market during January through September.

Chart: Bank of Japan estimates of approximately 112 and 43 years at the respective annual sales paces. Constant-pace arithmetic, not completion forecasts.

That’s why an increase of roughly 161% in annual book-value sales can coexist with a cautious exit. Spreading transactions over time gives buyers opportunities to adjust their portfolios and allows the BOJ to reassess execution if conditions deteriorate.

Officials say sales since January have gone smoothly, with no major effect on the market. The decision to accelerate also accounts for higher overall trading activity.

The 43-year estimate doesn’t establish that Japan’s market needs four decades to absorb the portfolio, or that the BOJ couldn’t finish dumping its bonds sooner under another policy.

The bank is accepting prolonged equity ownership in exchange for limiting the volume it puts before buyers now, and future officials will inherit both the remaining assets and the discretion to sell them.

Bitcoin’s exposure runs through the borrowing

A direct route runs from Japanese monetary policy to Bitcoin, since the yen carry trade has been a favorite strategy for financing large Bitcoin buys for years.

Traders who borrow yen and buy unhedged dollar-denominated investments (Bitcoin or others) owe yen debt against an asset priced in a foreign currency. That makes the exchange rate capable of eroding the trade even if the asset’s dollar price remains stable.

If the yen strengthens, converting the asset back produces fewer yen to repay the loan. Higher borrowing costs can further reduce the return, and lenders may require more collateral under the financing terms.

Investors who need cash can sell other holdings, including Bitcoin, which allows trouble in one part of a portfolio to affect assets with no direct connection to the original trade.

Unfortunately, we can’t know for sure whether this is happening now or at what scale. The BOJ’s ETF program and private investors’ financing are different, even if they can be affected by the same market currents.

Japan’s inflation outlook and yen funding are conditionally connected, but this still requires evidence of actual borrowing stress.

The latest foreign investment numbers make the need for precision concrete. During Oct. 18-24, investors covered by the Ministry of Finance’s weekly report recorded ¥92.6 billion of net disposals of foreign long-term debt, but bought ¥430.8 billion of foreign securities overall.

Purchases in other categories more than offset the debt reduction, so the numbers don’t describe a general withdrawal of Japanese money from foreign markets, nor does that debt category identify US Treasury sales or prove that proceeds were converted into yen.

The report covers designated major investors, and disposals include redemptions, so it measures securities transactions rather than investors’ funding needs.

Establishing a forced selling episode would require financing stress connected to position reductions. Declining futures open interest could help document deleveraging, but would not identify the currency borrowed.

For now, the Bank of Japan’s four-decade calculation captures the consequences of prolonged intervention: ending a purchase program can leave a central bank managing its investments for much longer than it spent building them.

Private investors will gradually take over that exposure, while the bank can slow its exit when conditions worsen.

Bitcoin becomes vulnerable when investors elsewhere need to sell assets to meet obligations, and the decisive difference is whether those investors can afford the patience Japan has built into its own program.