The yen sliding to a once-unthinkable ¥200 to the dollar level is now a risk — albeit an extreme one — for some investors.

Under siege from Japan’s wide interest-rate gap with other major economies and deepening concerns about Tokyo’s fiscal outlook, the yen has tumbled to a 1986 low and cemented its place as one of the worst-performing major currencies this past year.

Traders see little long-term relief from the Japanese government’s repeated warnings that it will take bold action to stem the decline. Any official intervention to bolster the yen is seen by many as a mere speed bump as investors judge Japan to be a laggard in raising interest rates to combat inflation, underpinning its structural weakness.