X0306 4 2018-07-09 0 0001631574 Wave Life Sciences Ltd. WVE 0001657709 Francis Chris C/O WAVE LIFE SCIENCES LTD., 733 CONCORD AVE. CAMBRIDGE MA 02138 0 1 0 0 See Remarks Ordinary Shares 2018-07-09 4 M 0 23900 2.48 A 45977 D Ordinary Shares 2018-07-09 4 S 0 23900 37.25 D 22077 D Ordinary Shares 2018-07-09 4 M 0 596 2.48 A 22673 D Ordinary Shares 2018-07-09 4 S 0 596 38.22 D 22077 D Share Option (right to buy) 2.48 2018-07-09 4 M 0 24496 0.00 D 2025-03-10 Ordinary Shares 24496 52572 D The option exercise and sale reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 14, 2018. The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $37.00 to $37.975 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The price reflected is the weighted-average sale price for shares sold. The shares were sold in multiple transactions and the range of sale prices for the transactions reported was $38.10 to $38.25 per share. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price. The share option represented a right to purchase a total of 126,174 ordinary shares, 25% of which became exercisable on April 15, 2015, and the remaining shares vest in 36 equal monthly installments thereafter. SVP, Corporate Development, Head of Emerging Areas /s/ Chris Francis 2018-07-11