The optical-interconnect and advanced-packaging rungs ran again on a dovish-Fed tape as Modine fell on a spin-off completion.

Applied Optoelectronics (AAOI) led the vertical, up 7.7% to $115.59, extending the optical-interconnect melt-up that began Thursday on Coherent's PhotonLink launch — the transceiver maker is now up roughly 231% year-to-date, with a beta near 3.8 that amplifies every leg. The move owns the optical-interconnect chokepoint directly: the bandwidth rung every AI accelerator cluster bottlenecks on as switch radix climbs. The rest of the rung came with it — Credo +4.0% to $218.64, Lumentum +3.8% to $1,085.42, and Coherent itself +5.6% to $337.04. A soft September payrolls print (+29k vs. +84k expected) firmed rate-cut odds and carried the Nasdaq to a record, lifting the whole datacenter buildout.

The laggard was Modine (MOD), down 5.8% to $178.20, on corporate-action mechanics rather than fundamentals: it completed the ~$946M Reverse Morris Trust spin-off and merger of its Performance Technologies unit into Gentherm, leaving a thermal-management pure play aimed at datacenter cooling and commercial HVAC, and Oppenheimer trimmed its target to $260 from $300. On the cooling-thermal chokepoint — the heat-rejection rung that gates rack density — the selling was due-bill and share-distribution noise around the separation, not a demand signal.

Breadth sat with advanced packaging and equipment. Camtek +7.4% to $165.19, Amkor +5.9% to $56.02, and ASE's US line +6.1% (its home listing closed +7.0%) carried the OSAT rung on AI/HPC packaging demand, with Onto Innovation +4.1% to $327.77. Substrates-materials firmed: Entegris +5.0% to $166.47, while SUMCO's wafer-squeeze narrative held even though its thin US line overstated the Tokyo session's roughly 1.6% gain. Lithography and process tools were bid — ASML +3.3% to $1,867.31, KLA +3.3% to $206.89 — and Broadcom added 3.3% to $355.14 on the accelerators rung.

The near-term calendar is conference-heavy. OCP Global Summit (San Jose, Oct 12–15) and SEMICON West (San Francisco, Oct 13–15) are the next venues where interconnect, advanced-packaging, and cooling roadmaps get set — directly relevant to the optics and packaging rungs that led. Intel's 14A external-customer decision window opens at year-end, the domestic-foundry validation signal the vertical is watching, and the OpenAI Q4 IPO listing window remains the private-compute wildcard that would reprice the neocloud rung.