The yen also gained against other currencies, stirring speculation Japanese authorities could be in the market again

The yen rose for a third straight session on Monday, keeping traders on alert for ​further intervention after Tokyo stepped into the foreign exchange market last week to support Japan’s currency.

Meanwhile, oil ‌prices dipped more than $4 a barrel.

Rising energy prices are expected to weigh more heavily on the Japan.

Japan conducted yen-buying ​intervention and will not hesitate to take further action, Japan’s finance ministry said on Monday.

The yen also gained against other currencies, stirring speculation Japanese authorities could be in the market again.

Dollar/yen 1.5-2 ​standard deviations above the long-term trend have been a useful guide for identifying when intervention risk enters the danger zone, said Stephen Spratt, ​APAC developed markets rates strategist at Societe Generale.

Currently this level is 162.72-164.96 area, he added.

The yen gained 1% in the Asian morning to a high of 155.20 per dollar, its strongest level in about three months, before paring some gains. It was last up 0.45% at 156.65.

A substantial build-up of short yen positions ​had occurred, and the unwinding of these positions tends to accelerate yen appreciation, Hirofumi Suzuki, SMBC’s chief forex strategist, said of Monday’s move.

The ​yen’s jump followed a more than 3% surge over two trading sessions at the end of last week. Japan’s finance ministry confirmed it had engaged in joint ‌yen-buying intervention ⁠with the U.S. on Friday, while Bank of Japan data showed Tokyo may have bought $58.97 billion worth of yen on Thursday.

The yen has been under pressure for years, undermined by the BOJ’s gradual approach to monetary policy tightening, which has kept yield differentials wide between Japan and the rest of the world.

Barclays analysts argued that even if the yen were to strengthen further in the near term, longer-term downward ​pressures remain in place.

Goldman Sachs strategist ​said that outside of a ⁠change in either the policy mix or global growth outlook, encouraging repatriation would be the most powerful policy for influencing the currency over a long period of time.

Market participants worried that Japan’s expansionary fiscal policy ​could weigh on the currency.