The Bank of Japan may be about to get serious - at the policy meeting on December 19, the market is widely expected to announce a 25 basis point interest rate hike, pushing the rate to 0.75%. Does this number sound inconspicuous? But it is the highest point since 1995. As soon as the news came out, the yen immediately strengthened, pulling directly from around 155 to the 154.56 range against the US dollar.

Behind this lies a bigger story: the rules of the game in global carry trading may be changing.

Over the past few years, countless investors have relied on the ultra-low interest rate of the yen to harvest wool - borrowing almost zero-cost yen and exchanging it for US dollars or directly smashing into high-volatility targets such as Bitcoin and US stocks. Now that Japan's interest rates are rising, the cost account of this transaction is suddenly not cost-effective. What will happen to those leveraged funds? Close the position, retreat, save your life first.

This is not good news for Bitcoin. In the rebound in November, the liquidity of the yen did not decrease. Now that the cost of funds is rising, those institutions and large investors who use leverage to play Bitcoin are likely to be the first to cut their positions. The structural selling pressure is here, and it is really hard to say whether the price can withstand it.

Even more troublesome is the chain reaction. A stronger yen often means global deleveraging - not only the crypto market, but also high-risk assets in the global stock market and emerging markets may suffer. When volatility rises, market sentiment is easy to collapse.

Historical experience tells us that once the central bank starts raising interest rates, the turning point of capital flows is not far away. The trigger pulled by the Bank of Japan this time may have a much more far-reaching impact than it seems on the surface.