ChipMOS filed NT$805.5 million in Advantest equipment orders that ran through a two-day, 25% drop

ChipMOS·+0.25% — ChipMOS, up 0.25 percent as of its last quote, a Taiwanese company that assembles and tests chips for other semiconductor makers, filed a receipt on November 10: a Form 6-K↗, the report foreign issuers lodge with the SEC, disclosing NT$805,498 thousand of machinery equipment and accessories bought from Advantest Taiwan▲+4.63% — Advantest Taiwan, up 4.63 percent today for manufacturing use ¹². The purchases run from April 8 to November 10, approved at the president's level ¹, and Taiwan's rules made the deal public once it crossed NT$500 million ². That window spans the entire selloff. In Tokyo, Advantest closed at ¥29,690 on November 10, up 4.63 percent ³.

A record half, then a quarter gone in two days

Advantest, with Teradyne, builds the automated test equipment every AI accelerator and memory stack must pass before it reaches a datacenter. Its first half of fiscal 2026, the six months to September 30, set records on every line: net sales of ¥845.2 billion, up 60.5 percent; operating income of ¥456.8 billion, up 96.5 percent; net income of ¥368.1 billion, up 116.8 percent ⁴. It raised the full-year forecast with them ⁴.

Tokyo's answer was to sell the record. Advantest fell 14.7 percent on November 5 and another 12.2 percent on November 6↗; one after the other, the two sessions took about 25 percent ⁵. The Nikkei 225, Japan's benchmark, lost 5.96 percent to 57,434.77, more than 20 percent under its June 22 peak of 72,831.73 ⁵.

The trigger was political: after the Democrats' midterm sweep, investors priced tighter datacenter rules, following a 5.5 percent Nasdaq fall ⁶. And ¥57.0 billion of the half's pretax profit was financial income, ¥54.2 billion of it valuation gains, a finance tailwind rather than tester demand ⁷.

The bottleneck both earnings calls named was supply

Teradyne▲+1.25% — Teradyne, up 1.25 percent today, the other half of the duopoly, met the same mood. Its third-quarter revenue↗ was $1,306 million, up 70 percent and above the top of its own guidance, with a fourth-quarter range of $1,250–1,350 million ⁸; as The Inference noted beforehand, that sits under the $1.33 billion June-quarter record. The stock still fell about 6.6 percent ⁹.

More than 60 percent of Teradyne's sales are AI-related, and five customers are 44 percent of revenue ¹⁰. The research firm SemiAnalysis read both calls and put the market's size and its ceiling in one line: "the ATE TAM is growing on AI compute, and supply, not demand, is the constraint through 2027" ¹¹. Advantest's own release agrees, expecting a record tester market in calendar 2026 and saying demand for memory and other key components still exceeds supply ⁴.

One receipt, and two dates that decide

The filing covers a single customer, and the bears hold real cards: a Q4 guide traders read as a plateau ⁹, a regulation risk that lives in Congress rather than the fab ⁶, and a Nikkei that ran far on AI enthusiasm before it fell ⁵.

The deciding dates are booked. Advantest holds its investor fireside chat on November 12 ³ and files its semi-annual securities report on November 13, with an interim dividend of ¥49 payable December 1 ⁴.

The tell is parts: if management still says it cannot source components fast enough, the raised forecast is a factory problem, and factory problems leave evidence. Two sessions took a quarter off Advantest's value, and the purchase orders kept coming all the way down.