X0306 4 2021-01-27 1 0000912242 MACERICH CO MAC 0000937567 ONTARIO TEACHERS PENSION PLAN BOARD 5650 YONGE STREET, 3RD FLOOR TORONTO, ONTARIO A6 M2M 4H5 ONTARIO, CANADA 0 0 1 0 0001625247 1700480 ONTARIO INC 20 QUEEN STREET WEST TORONTO A6 M5H 3R4 ONTARIO, CANADA 0 0 1 0 Common Stock, par value $0.01 per share 2021-01-27 4 S 0 7000000 19.25 D 17562964 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 4951814 19.09 D 12611150 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 6201597 20.26 D 6409553 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 4080364 21.21 D 2329189 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 706959 22.03 D 1622230 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 372230 22.75 D 1250000 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 400000 24.93 D 850000 I See Note Common Stock, par value $0.01 per share 2021-01-27 4 S 0 850000 25.75 D 0 I See Note The shares of Common Stock were sold in a block trade at a price of $19.25 per share. The shares of Common Stock were owned directly by 1700480 Ontario Inc., which is a wholly owned subsidiary of Ontario Teachers' Pension Plan Board. Ontario Teachers' Pension Plan Board was an indirect beneficial owner of such reported securities. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $18.60 to $19.59. The reporting persons undertake to provide the issuer, any stockholder 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 within the ranges set forth in footnotes (3) and (9) to this Form 4. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $19.60 to $20.59. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $20.60 to $21.59. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $21.60 to $22.59. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $22.60 to $23.59. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $24.60 to $25.59. The price reported in Column 4 is a weighted average price per share. The shares of Common Stock were sold in multiple transactions at prices ranging from $25.60 to $26.59. /s/ Sandra Hardy, Authorized Person on behalf of 1700480 Ontario Inc. 2021-01-28 /s/ Rossana Di Lieto, Senior Managing Director and Chief Compliance Officer on behalf of Ontario Teachers' Pension Plan Board 2021-01-28