The recent earthquake in Taiwan did have an impact on TSMC’s production, but probably not as great as some in the press have indicated: TSMC loses 40K wafers in quake. This blog gives a more careful reading of the announcement. What it comes down to is “1.5 days loss of wafer movement for the company in total.”
Regardless of whether or not they had to scrap any wafers, 1.5 days of downtime is 1.5 days of not producing wafers in a facility that is costing you an obscene amount of depreciation when it’s not producing wafers. It’s not actually 1.5 days for every facility they have, but they averaged it out. It was obviously worse in Tainan, with Hsinchu barely affected. 1.5 days for the company as a whole is roughly 1.6% of a quarter. That lost time is revenue delayed, though probably not lost. If they’re not already at capacity, they can probably make up the missing wafers for their quota. At the end, it comes down to, “How many wafers did you ship this quarter? How much did you get for them?” As I said, revenue delayed, not lost, but there is a cost associated with that.