Samsung SDI surges 8% as Samsung Electronics tumbles on shareholder return disappointment

Samsung SDI shares surged more than 8% on Monday even as Samsung Electronics tumbled after the tech giant unveiled a shareholder return plan worth up to 110 trillion won ($79.5 billion).

Samsung SDI was trading up 8.58% at 519,000 won as of 10:25 a.m. Monday, according to Korea Exchange, having briefly climbed as high as 522,000 won intraday.

The battery affiliate's rally stood in sharp contrast to the broader Samsung group, where Samsung Electronics, Samsung Life Insurance and Samsung C&T all fell in the first regular session since the shareholder return announcement.

Analysts attributed Samsung SDI's gains largely to its recent decision to sell its stake in Samsung Display.

Samsung SDI disclosed after Friday's market close that it would sell its Samsung Display stake for approximately 4.45 trillion won.

The company did not specify how it plans to use the proceeds, but the market widely expects the funds to go toward capital investment at Synergy Cells, a battery factory under construction in New Carlisle, Indiana.

"It is positive that the financing method for expanding North American ESS battery capacity has become more concrete," Park Hyun-su, an analyst at Shinyoung Securities, said in a note Monday. "Since Synergy Cells is set to convert to a standalone corporate structure, unlike a joint-venture arrangement, 100 percent of battery profits can be recognized as controlling shareholder net profit."

The optimism spilled over into the broader battery and secondary-cell sector, lifting related stocks on renewed investor interest.

Battery stocks had languished for an extended period, weighed down by slowing electric vehicle demand, inventory corrections and falling raw material prices.

Sentiment has been improving as inventory adjustments near completion and demand from ESS and AI data centers emerges as a new growth driver for the industry.

At the same time, LG Energy Solution was up 3.64% at 356,000 won, while SK Innovation, the parent of SK On, gained 5.29% to trade at 131,400 won.

Among battery materials makers, L&F jumped more than 16% and Posco Future M rose over 9%.

Samsung group affiliates, by contrast, were broadly weaker.

Samsung Electronics announced Friday a shareholder return plan of 90 trillion to 110 trillion won for this year. The announcement fell short of market expectations that had built around a figure of as much as 200 trillion won, widening the gap between the actual plan and investor hopes.

Samsung Life Insurance and Samsung C&T had been seen as direct beneficiaries of an expanded Samsung Electronics shareholder return, prompting a string of brokerages to raise their target prices — yet both stocks moved in the opposite direction.

Samsung Electronics was down 6.39% at 263,500 won, Samsung Life Insurance fell 9.28% to 298,000 won, and Samsung C&T dropped 7.33% to 366,500 won.

Analysts in the brokerage community, however, maintained that Samsung Electronics and SK Hynix — which earlier announced a 40 trillion won shareholder return plan — would provide long-term support for domestic market liquidity.

"Large-scale shareholder return plans by leading stocks will serve as a supply-demand safety net for the broader domestic market," said Han Ji-young, an analyst at Kiwoom Securities. "Even if semiconductor stocks see heightened share price volatility after the opening bell, it will not last long."