Since TSMC announced in 2020 that it would build factories in the US, the market has closely watched how overseas fab costs would affect operations. TSMC’s long-running Arizona buildout has entered a new phase after five years of construction, with the company’s first 4nm fab now ramping production and contributing to profits. The second fab is set to enter equipment move-in in the fourth quarter of 2026, the third fab is scheduled for move-in in September 2027, and the fourth has already begun site preparation.