X0206 3 2018-07-12 0 0001561627 ExOne Co XONE 0001746900 Helfrich Jared Adam 127 INDUSTRY BOULEVARD NORTH HUNTINGDON PA 15642 0 1 0 0 Chief Commercial Officer Common Stock 333 D Stock Option (right to buy) 7.91 2022-08-14 Common Stock 15000 D Stock Option (right to buy) 10.10 2027-02-10 Common Stock 8000 D The original option grant for 15,000 shares vested with respect to 7,500 shares on August 14, 2017 and will vest with respect to the remaining 7,500 shares on August 14, 2018. The original option grant for 8,000 shares vested with respect to 2,666 shares on February 10, 2017 and with respect to 2,667 shares on February 10, 2018; the remaining 2,667 shares will vest on February 10, 2019. See attached Exhibit 24 (Power of Attorney). s/ Loretta L. Benec, attorney-in-fact for Jared A. Helfrich 2018-07-23