Tech Stock Valuation

previously are broadly descriptive of all such goodwill write-off announcements

or more narrowly relevant for certain manufacturing firms.

For n = 43 goodwill write-off announcements by manufacturing firms (20 ≤

SIC < 40), Table 8.2 shows material negative stock-price reactions tied to good-

will write-offs using the market-model approach (–3.32%, t = –4.36), the mean-

adjusted approach (−3.43%, t = –4.33), and the market-adjusted approach

(−3.77%, t = –4.87). For n = 10 goodwill write-off announcements by firms in the

Industrial and Commercial Machinery industry group (SIC = 35), large negative

stock-price reactions tied to goodwill write-offs are e