Arbitrage trading retreat boosts a significant rise in the yen, while expectations for the Bank of Japan's interest rate hikes continue to heat up.

As traders increased their bets on further rate hikes by the Bank of Japan, a large-scale unwinding of yen financing carry trades pushed the yen to its highest level against the dollar in a month. On Thursday, the yen surged over 2%, and on Friday it maintained its upward momentum, approaching the levels seen during the May intervention by the Japanese Ministry of Finance. Earlier, Bank of Japan Governor Kazuo Ueda and committee member Kiyohiko Nishimura both made hawkish remarks this week, suggesting a significant rate hike at the policy meeting on September 18, which further fueled market expectations. According to data from the Chicago Mercantile Exchange, on Thursday, the trading volume of the dollar/yen call options due this month was more than two and a half times that of put options, indicating that traders were focusing on unwinding their short yen positions. When the yen appreciates against the dollar, the value of call options rises. Sagar Sambrani, a senior forex options trader at Nomura Securities in London, stated, "The current market is experiencing significant unwinding of yen financing carry trades, while there is a strong interest in holding yen against other G10 currencies in the medium term. The market generally believes that the era of easy carry trading is over, and that there may have been a substantial shift in the scale of Japan's cross-border capital flows." The yen has long been seen as an ideal funding currency due to Japan's very low borrowing costs. Carry traders borrow yen and invest in higher-yielding assets, profiting from the interest rate differential as long as the yen remains stable or weak. However, with rising expectations for a tightening policy from the Bank of Japan, yields on Japanese government bonds have risen, strengthening the yen and increasing volatility, putting this trading logic under significant pressure. This week, the yield on Japan's two-year government bonds has risen by about 14 basis points, and the swap market pricing indicates a high probability of a 25 basis point rate hike at the September 18 meeting, with approximately three additional hikes of the same magnitude expected by July next year. Compared to the average pace of two hikes per year since 2024, this means a significant acceleration in the rate hike pace. The dollar was not the only currency impacted by the unwinding of carry trades yesterday. High-yield currencies such as the Brazilian real, South African rand, and Mexican peso all fell over 1% against the yen. Strategist Brendan Fagan remarked, "The 2% single-day surge of the yen against the dollar is the clearest signal thus far that a more proactive Bank of Japan is the best remedy for a weak yen." The shorts on the yen still have room to extend. According to the latest data from the Commodity Futures Trading Commission, as of the week ending August 25, leveraged funds held net short positions in yen totaling 81,619 contracts, while asset management firms had short positions of 18,284 contracts. The market's judgment that the Bank of Japan would raise rates this month while maintaining flexible tightening is prompting investors to continue to reduce their short positions. Traders noted that Japanese exporters have also increased their selling of dollars against the yen, further supporting the yen's appreciation. Bank of America stated that this round of yen rebound reflects a broad change in market sentiment. Ivan Stamenovic, head of G10 currencies trading for the Asia-Pacific region at Bank of America in Hong Kong, pointed out, "The move in dollars against the yen is not driven by unilateral actions in a specific market but rather reflects a reconfiguration of overall risk positions in response to events over the past 48 hours." Returning to the London market, discussions about the "collapse" of yen financing carry trades have spread across trading desks. Mizuho Bank noted that market sentiment had clearly shifted this week, prompting investors to accelerate the unwinding of crowded short yen and Japanese government bond positions. Masayuki Nakajima, a senior strategist at Mizuho in London, summarized, "The core driving factor is the large-scale unwinding of short positions in the yen, particularly among hedge fund accounts. At the same time, expectations for the Bank of Japan to continue tightening policies are also steadily increasing."