ASE is the dominant global OSAT (44.6% share of TrendForce top-10 OSAT revenue in 2024, ~3x #2 Amkor) and the primary structural beneficiary of the chiplet-era advanced packaging supply-demand imbalance. The Q1 2026 print (LEAP US$1.6B = +167% YoY, ATM GM 26% beating 24.5% guide, FY26 LEAP guide raised 10% to US$3.5B+, FY26 capex raised intra-year to ~US$8.5B for 2027 ramp) materially exceeds the prior bull-case trajectory and validates that ASE has transitioned from cyclical backend assembler to the de facto second supply chain for AI accelerator packaging. SPIL is TSMC's primary CoWoS outsourcing partner (60-80K wafers in 2026 against TSMC in-house 120-130 kwpm by end-2026, both still fully booked through 2027 with NVIDIA reserving >50%); CoPoS panel pilot at TSMC slips to 2028 mass production, leaving FOPLP/FOCoS-Bridge as the only credible alternatives over the next 24 months. At $32.64/ADS the multiple has fully closed the substrate-pkg discount — the question is no longer whether the structural thesis works, but whether the price already discounts a 2027-28 trajectory that requires perfect execution on US$8.5B+ capex with negative FCF.