Amkor tripled its Gwangju plant to $2.22 billion on a county wastewater deal; results land Oct. 26

Shovels go in on a plan tripled since June

On the morning of October 19, Amkor Technology▲+1.73% — Amkor Technology, up 1.73 percent today Korea broke ground on four new buildings at K4↗, its advanced packaging plant in Buk-gu, Gwangju, with the city's mayor and a trade-ministry director in attendance ¹. Amkor, the largest US-headquartered provider of outsourced semiconductor assembly and test, the back-end work of packaging and testing other companies' chips, plans 3 trillion won ($2.22 billion) at the site through 2031, triple the 1.01 trillion won announced in June ².

Two buildings are due in the second half of 2027 and two more in the first half of 2028, when mass production begins ¹. The two local reports split on jobs: 1,500 new positions against more than 2,000 by 2031 ²¹.

A wastewater pact unlocked the bigger number

The limit on the expansion was wastewater treatment capacity, not demand or money ². Amkor's June blueprint of about 1 trillion won could not go higher because existing treatment facilities were at capacity, so the company asked the city of Gwangju for help on September 16 ².

Gwangju opened talks with neighboring Jangseong county the next day and signed a memorandum the day after to share its public treatment plant↗; with spare capacity confirmed, Amkor raised the project to 3 trillion won ². Amkor ranks second globally among specialized semiconductor back-end processors, and Gwangju will now run a standing consultative body through the roughly four-year construction ².

Tripling the build widens the gap between capex and cash

The acceleration lands on a stretched ledger. Amkor guides 2026 capital spending to $2.5–3.0 billion against $382 million of first-half operating cash flow ³. Filings show second-quarter capex of $435 million↗, the highest of the past twelve quarters, and $652 million for the first half; reaching even the $2.5 billion floor implies roughly $1.85 billion of second-half spending, nearly three times the first-half pace ⁴.

Arizona climbed the same ladder. The Peoria campus went from $7 billion at its October 2025 groundbreaking to about $12 billion announced on September 28↗, after customer commitments surpassed the 33,000 square meters of cleanroom planned for Phase 1 ⁵⁶. Nvidia's▲+1.49% — Nvidia, up 1.49 percent today $1.5 billion backs that US capacity as a prepayment, expected from 2027 and returned as US services rather than booked revenue ⁷³.

Depreciation starts two to three years before Honam demand

Gwangju's buildings open between late 2027 and mid-2028, inside the Honam cluster, a planned Samsung-SK hynix▲+5.64% — SK hynix, up 5.64 percent today fab zone around Gwangju backed by 800 trillion won of investment and targeting first mass production in 2030 ¹². Depreciation on the new buildings begins when they enter service, two to three years before that cluster demand arrives ¹.

Nvidia and Apple anchor the other side

The bull case carries evidence. The June quarter was Amkor's best second quarter on record at $1.9 billion in sales, and computing, its data-center segment, is guided up about 30% from the prior quarter on AI demand ³. Apple▲+0.38% — Apple, up 0.38 percent today and Nvidia are named customers of the Peoria campus ⁵.

Hanmi Semiconductor, the Korean maker of the bonders that stack high-bandwidth memory (HBM) chips, opened a San Jose support hub on October 16 to service the US packaging buildout ⁸. The market keeps selling anyway: ten straight lower closes took the shares to $41.82, 57% below the 52-week high of $96.68, and insiders sold $992 million of stock over the past year with no purchases ³⁹.

The October 26 report tests the cash behind the build

Results land after the close on October 26 ⁹. Consensus sits at $2.03 billion of revenue and $0.774 a share↗, against company guidance of $1.95–2.05 billion and $0.72–0.82 ⁹³. The number to watch sits below the earnings line: whether second-half operating cash flow, or new financing, covers the roughly $1.85 billion of implied second-half capital spending before the first Gwangju buildings begin depreciating in 2027 ³⁴.