沪硅产业（688126.SS）：300mm晶圆产能爬坡支撑增长，光子SOI进入量产爬坡

Goldman Sachs maintains a Sell rating on NSIG (688126.SS) with a revised 12-month target price of Rmb16.1 (from Rmb16.9), implying 11.0% downside from the Rmb18.08 price, based on a 57.3x 2027E target P/E derived from the global peer correlation between P/E and net income growth. NSIG continues to ramp 300mm wafer capacity, which has reached 1.0mn wpm across its Shanghai and Taiyuan sites, targeting 1.2mn wpm by end-2026; 300mm wafer sales volume rose over 90% YoY in 1H26 on new customer additions and product expansion across logic, memory, CIS and power applications. The continued ramp and mix upgrade toward prime wafers support longer-term revenue growth, but higher depreciation and pressure on 200mm wafers weigh on near-term margins. Photonics SOI wafers are expected to enter volume shipments in 2027, a medium-term growth opportunity driven by AI optical demand. The firm widens its 2026E net loss estimate to Rmb1,061mn from Rmb911mn and revises 2027E-28E net income by -1%/+2%, with