X0306 5 2020-01-03 0 0 1 0000851520 EXPONENT INC EXPO 0001193221 JOHNSTON PAUL R 149 COMMONWEATH DRIVE MENLO PARK CA 94025 1 0 0 0 Common Stock 2019-12-23 4 S 0 8291 69.0797 D 46605 D Dividend Equivalent Rights 2020-01-03 5 A 0 297 A 2020-03-11 2020-03-11 Common Stock 297 1247 D Per 10b5-1 trading plan entered into on July 26, 2019. Reporting a sale of 8,291 shares on 12/23/19 that was not previously reported on a Form 4. Due to a calculation error associated with a stock split, the total shares outstanding was over reported by 4,000 shares on the form 4s dated 3/13/19, 10/22/19, 10/25/19, 10/30/19, 11/04/19, 11/07/19, 11/12/19, 11/15,19, 11/20/19, 11/25/19, 12/02/19, 12/5/19, 12/10/19, 12/13/19, and 12/18/19. The total reflected here corrects the misreported amounts. 1-for-1. The dividend equivalent rights accrued with respect to RSUs, pursuant to dividends earned in 2019. Not applicable. By: Wendy Whitehouse For: Paul R. Johnston 2020-02-14