Rising interest rates in Japan will do little to rescue the beleaguered yen as long as there’s demand for one of the most lucrative bets in foreign exchange, traders say.

The yen remains one of the hottest macro assets to sell as part of so-called carry trades — a strategy that involves borrowing Japan’s currency for almost nothing, to buy dollars and earn more than 5%. The weakening yen and strengthening greenback are increasing the attractiveness of the carry trade, by boosting its total return over the last year to 18%.

That’s setting up a potentially tense showdown with Japanese authorities who appear bent on stymieing the yen’s seemingly excessive weakness. The Bank of Japan’s next policy meeting may be just over two weeks away, but some market participants are already warning the yen is at risk of falling back to around a 34-year low of ¥160.17 as long as these carry strategies remain in vogue.