Japanese Shares End Lower as US-Iran Talks Falter, Naval Blockade Looms (UPDATE 1)

Reuters

12:41 JST, April 13, 2026 (updated at 16:20 JST)

TOKYO, April 13 (Reuters) – Japanese shares ended lower on Monday as the U.S.-Iran peace talks collapsed over the weekend and the American Navy prepared a blockade on Iranian ports, casting fresh doubts about the durability of an ongoing ceasefire.

The Nikkei fell 0.7% to close at 56,502.77, after posting last week its steepest weekly gain in more than a year.

The broader Topix slid 0.5% to 3,723.01.

U.S. President Donald Trump said on Sunday the U.S. Navy would start blocking the Strait of Hormuz, a choke point for 20% of the world’s daily energy supplies that Iran effectively closed since the war started in late February. The announcement drove oil prices to jump above $100 a barrel in early trade on Monday.

“I don’t think there are that many investors who expected everything to be agreed (at the weekend talks) and for everything to go smoothly,” said Shuutaro Yasuda, market analyst at Tokai Tokyo Intelligence Laboratory.

“That said, it’s obviously not good news, so stocks are falling. But I think the reason we’re not seeing a really extreme risk-off move is exactly that.”

Market breadth was negative, with 158 stocks falling versus 63 advancing in the Nikkei.

Toto shed as much as 8.8%, its biggest drop since August 2024, after the Nikkei business daily reported that the bathroom fixtures and sanitary ware maker has suspended orders for unit baths due to a shortage of organic solvents made from petroleum-derived naphtha. It ended Monday’s trading down 7.2%, the biggest loser in the Nikkei index.

Shares of Ibiden 4062.T, a chip packaging and electronics firm, fell 5.1% while semiconductor manufacturing equipment maker Tokyo Electron sank 3.6%.

On the flip side, Dentsu Group jumped as much as 10.6%, becoming the key gauge’s top percentage gainer, after an updated shareholder composition report showed that an entity linked to veteran activist investor Yoshiaki Murakami had appeared on the shareholder list of Japan’s largest advertising and marketing company.

Yaskawa Electric, an industrial robot and motion control systems maker, surged 7.1% following strong earnings and a dividend hike announced last week. Japan’s top oil and gas explorer Inpex gained 3.1%.