HAWAIIAN ELECTRIC CO INC

During the three months ended June 30, 2026, no director or officer of HEI or Hawaiian Electric (as defined in Exchange Act Rule 16a-1(f))adopted orterminated a “Rule 10b5-1 trading arrangement” or “non-Rule 10b5-1 trading arrangement,” as each term is defined in Item 408 of Regulation S-K.

Effective August 5, 2026, the Boards of Directors of the Company and Hawaiian Electric approved the amendment and restatement of the Company’s and Hawaiian Electric’s bylaws, respectively (in each case, as so amended and restated, the “Amended Bylaws”).

The Amended Bylaws establish the office of chief executive officer (CEO), and substitute the CEO for the president with respect to certain authority and responsibilities previously vested in the president, including with respect to certain matters related to the conduct of shareholder meetings (Article II, Sections 2 and 3; Article III, Sections 2 and 5; Article IV) and the appointment, removal and determination of the duties and compensation of subordinate officers (Articles V-XV).

In addition, the Amended Bylaws make conforming and clarifying changes reflecting the establishment of the CEO position and the allocation of authority among the Company's officers.

The foregoing summary is qualified in its entirety by reference to the full text of the Amended Bylaws, copies of which are included as Exhibit 3.1 and Exhibit 3.2 to this report and incorporated by reference herein.