None of them had news. Over two sessions on 18 and 19 August, every listed supplier of the parts that go inside chipmaking tools — gas-delivery panels, probe cards, ion implanters, test handlers — dropped double digits at once. FormFactor fell 17.1%, Ichor 16.6%, MKS 13.0%, Veeco 12.8%, Axcelis 12.3% and Cohu 11.9%. Lam Research, which buys from several of them, fell 10.7%. Nvidia fell 2.1%.

The trigger sat in the bond market. The 30-year Treasury yield topped 5.33% on 18 August, a 19-year high, on sticky core inflation and deficit concerns, and the Philadelphia Semiconductor Index fell 4.96% that day. Two sessions were not the whole story, though: this rung has been bleeding since midsummer. Ichor is 45.5% below its 30 June close, Veeco 42.9%, MKS 36.7%, Axcelis 34.0% from its June high and FormFactor 28.1%.

Why this layer is the most rate-sensitive rung

These firms are paid a slice of someone else's tool, and the slice is booked late. Ichor's customers are now placing purchase orders six months out — a pattern management called abnormal. FormFactor's new Farmers Branch plant does not turn accretive until early 2028. Veeco's $200m advanced-packaging order, won in the June quarter, is mostly for 2027 delivery. Earnings power parked three years out is exactly what a 5.33% long bond discounts hardest.

What did not happen was a cut to the spending that feeds them. Lam Research raised its 2026 wafer fab equipment forecast to the low $150bn range from $140bn. Applied Materials guided its next quarter to $10.25bn, up 51% year on year on "unprecedented" demand, and said leading-edge logic, DRAM and advanced packaging would be about 80% of equipment-market growth in 2026 and 2027.

FormFactor: the numbers went the other way

FormFactor makes probe cards — the consumable interfaces that test chips while they are still on the wafer, designed in-house and sold against Japanese rivals MJC and JEM. June-quarter revenue rose 31.9% to $258.2m. Gross margin reached 50.7% against 37.2% a year earlier, and gross profit rose 80%; operating income rose more than fourfold. DRAM probe cards set a record on HBM4, the next generation of stacked memory, with high-bandwidth memory roughly two-thirds of DRAM revenue — and advanced HBM cards carry five to ten times the selling price of legacy ones. Foundry and logic did not stall either: a probe card for Nvidia's Rubin GPU is qualified and ships for revenue this quarter. Capacity, not demand, is the constraint until Farmers Branch ramps.

Against that, the shares trade at 21.8x trailing gross profit, versus 35.3x at the 30 June peak and 23.1x in February — the cheapest in six months, on a trailing gross-profit base 38.6% larger than a year ago. The honest caution is mix: September DRAM revenue is guided flat, shifting toward commodity DDR, which carries far less test content per wafer than an HBM stack.

Ichor: better business, still the expensive way to own it

Ichor assembles gas and fluid-delivery modules to other firms' drawings; Lam and Applied were 76% of its 2025 revenue. The recovery is real — revenue up 22.7% to $294.8m, gross margin back to 13.9% from a 4.6% trough, full-year guidance raised on 3 August to at least 30% growth, with internal content rising toward 35% of the bill of materials. But at 20.8x trailing gross profit it is still above its 19.0x February level, and 2.1x Ultra Clean's 9.7x for the same contract gas-panel work at a fatter 16.1% margin. Its $200m share sale was struck at $80.70; the stock closed at $61.21. The shares fell 12.8% after the print as negative operating cash flow overshadowed the raise.

Axcelis: the one where selling and fundamentals agree

Axcelis sells ion-implantation systems into mature-node, power-device and Chinese fabs — not the leading-edge logic, DRAM and packaging that Applied says will carry 80% of equipment growth. June-quarter revenue rose 10.6% to $215.2m, but gross margin slipped to 42.4% and operating income fell 30%. Trailing gross profit is 7.4% lower than a year ago; annual revenue has fallen two straight years, from $1.13bn in 2023 to $839m in 2025. Bookings roughly matched systems revenue, leaving backlog at $451.6m. China was 46% of the quarter. It is the only name here whose forward multiple of gross profit, 10.71x, sits above its trailing 10.43x — consensus expects the gross-profit dollars to shrink. It is also 59% more expensive than in February, and Applied holds about 63% of the implant market to Axcelis's 21%. Its $4.4bn all-stock merger with Veeco still awaits China's antitrust regulator, which moved the case onto a longer standard review.

The other three fall on the growing side. MKS, which has content on roughly 85% of wafer fab equipment, grew revenue 28.3% to $1.25bn and saw its multiple of trailing gross profit compress from 16.9x to 9.9x while that gross profit rose to $1.92bn. Cohu raised full-year guidance to about 35% growth with computing orders up 150%. Veeco raised revenue guidance but cut earnings guidance to fund 2027 capacity — the clearest statement that this layer is spending now for revenue later.

The setup

Where it stands — A rate shock repriced the whole sub-tool layer uniformly, but only Axcelis's shrinking gross profit matches the selling. Would confirm — FormFactor's September quarter landing near $270m with non-GAAP gross margin at the guided 54%. Would invalidate — Lam or Applied cutting 2027 equipment-spending guidance, turning a discount-rate move into a demand call. Watch next — Axcelis's next systems bookings print and China's SAMR ruling on the Veeco merger, expected before year-end. Valuation — FormFactor 21.8x trailing and 19.0x forward gross profit, against 35.3x on 30 June; Axcelis 10.43x trailing, 10.71x forward.