Description of Common Stock

As of December 31, 2020, MacroGenics, Inc. (“we”, “our” and “us”), has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended: common stock, par value of $0.01 per share (Common Stock).

The following description of our Common Stock is a summary and does not purport to be complete. It is subject to and qualified in its entirety by reference to our Amended and Restated Certificate of Incorporation, as amended (our Certificate of Incorporation), our Certificate of Correction of our Certificate of Incorporation (our Certificate of Correction), our Amended and Restated By-laws (our By-laws) and applicable provisions of the Delaware General Corporation Law (DGCL). Our Certificate of Incorporation, Certificate of Correction and By-laws are included as exhibits to the Annual Report on Form 10-K of which this Exhibit 4.2 forms a part. We encourage you to carefully read our Certificate of Incorporation, Certificate of Correction and By-laws and the applicable provisions of the DGCL for additional information.

Under our Certificate of Incorporation, we have the authority to issue 125,000,000 shares of our Common Stock.

Our Common Stock is listed on the Nasdaq Global Select Market under the symbol “MGNX.” The rights, preferences and privileges of holders of our Common Stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock we may issue in the future.

The outstanding shares of our Common Stock are duly authorized, validly issued, fully paid and non-assessable.

Holders of our Common Stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders and do not have cumulative voting rights. An election of directors by our stockholders shall be determined by a plurality of the votes cast by the stockholders entitled to vote on the election. Subject to the supermajority votes for some matters, other matters shall be decided by the affirmative vote of our stockholders having a majority in voting power of the votes cast by the stockholders present or represented and voting on such matter.

Holders of our Common Stock are entitled to receive proportionately any dividends as may be declared by our board of directors, subject to any preferential dividend rights of any outstanding preferred stock.

In the event of our liquidation or dissolution, the holders of our Common Stock are entitled to receive proportionately all assets available for distribution to stockholders after the payment of all debts and other liabilities and subject to the prior rights of any outstanding preferred stock.

Holders of our Common Stock have no preemptive, subscription, redemption or conversion rights. The rights, preferences and privileges of holders of our Common Stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Computershare Trust Company, Inc. is the transfer agent and registrar for our Common Stock.

Delaware law contains, and our Certificate of Incorporation and our By-laws contain, provisions that could have the effect of delaying, deferring or discouraging another party from acquiring control of us. These provisions, which are summarized below, are expected to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors.

Authorized but Unissued Shares. The authorized but unissued shares of our Common Stock will be available for future issuance without obtaining stockholder approval and the authorized but unissued shares of our preferred stock are available for future issuance. These additional shares may be utilized for a variety of corporate purposes, including future public offerings to raise additional capital, corporate acquisitions, and employee benefit plans. The existence of authorized but unissued shares of our Common Stock and preferred stock could render more difficult or discourage an attempt to obtain control over us by means of a proxy contest, tender offer, merger or otherwise

Removal of Directors. A director may be removed only for cause and only by the affirmative vote of the holders of at least 75% of the votes that all of our stockholders would be entitled to cast in an annual election of directors. Any vacancy on our board of directors, including a vacancy resulting from an enlargement of our board of directors, may be filled only by vote of a majority of our directors then in office.

Staggered Board of Directors. Our Certificate of Incorporation provides for a staggered board of directors consisting of three classes of directors. Directors of each class are chosen for three-year terms upon the expiration of their current terms and each year one class of our directors will be elected by our stockholders. Additionally, there is no cumulative voting in the election of directors. This classified board provision could have the effect of making the replacement of incumbent directors more time consuming and difficult. At least two annual meetings of stockholders, instead of one, will generally be required to effect a change in a majority of our board of directors. Thus, the classified board provision could increase the likelihood that incumbent directors will retain their positions. The staggered terms of directors may delay, defer or prevent a tender offer or an attempt to change control of us, even though a tender offer or change in control might be believed by our stockholders to be in their best interest.

Stockholder Action by Written Consent; Special Meetings. Our Certificate of Incorporation provides that any action required or permitted to be taken by our stockholders must be effected at a duly called annual or special meeting of such holders and may not be effected by any consent in writing by such holders. Our Certificate of Incorporation and By-laws also provide that, except as otherwise required by law, special meetings of our stockholders can only be called by our chairman of the board, our chief executive officer or our board of directors.

Advance Notice Requirements for Stockholder Proposals. Our by-laws have established an advance notice procedure for stockholder proposals to be brought before an annual meeting of stockholders, including proposed nominations of persons for election to our board of directors. Stockholders at an annual meeting will only be able to consider proposals or nominations specified in the notice of meeting or brought before the meeting by or at the direction of our board of directors or by a stockholder of record on the record date for the meeting who is entitled to vote at the meeting and who has delivered timely written notice in proper form to our secretary of the stockholder’s intention to bring such business before the meeting. These provisions could have the effect of delaying until the next

stockholder meeting stockholder actions that are favored by the holders of a majority of our outstanding voting securities.

Amendment of Our Certificate of Incorporation and By-laws. The DGCL provides generally that the affirmative vote of a majority of the shares entitled to vote on any matter is required to amend a corporation’s certificate of incorporation or by-laws, unless a corporation’s restated certificate of incorporation or by-laws, as the case may be, requires a greater percentage. Our By-laws may be amended or repealed by a majority vote of our board of directors or by the affirmative vote of the holders of at least 75% of the votes that all of our stockholders would be entitled to cast in any annual election of directors. In addition, the affirmative vote of the holders of at least 75% of the votes that all of our stockholders would be entitled to cast in any annual election of directors is required to amend or repeal or to adopt any provisions inconsistent with any of the provisions of our Certificate of Incorporation described above under “Removal of Directors” and “Stockholder Action by Written Consent; Special Meetings.”

Delaware Business Combination Statute. We are subject to Section 203 of the DGCL. Subject to specified exceptions, Section 203 of the DGCL restricts some types of transactions and business combinations between a corporation and a 15% stockholder. A 15% stockholder is generally considered by Section 203 to be a person owning 15% or more of the corporation’s outstanding voting stock. Section 203 refers to a 15% stockholder as an “interested stockholder.” Section 203 restricts these transactions for a period of three years from the date the stockholder acquires 15% or more of our outstanding voting stock. With some exceptions, unless the transaction is approved by the board of directors and the holders of at least two-thirds of the outstanding voting stock of the corporation, Section 203 prohibits significant business transactions such as:

•a merger with, disposition of significant assets to or receipt of disproportionate financial benefits by the interested stockholder; and

• any other transaction that would increase the interested stockholder’s proportionate ownership of any class or series of our capital stock.

The shares held by the interested stockholder are not counted as outstanding when calculating the two-thirds of the outstanding voting stock needed for approval.

The prohibition against these transactions does not apply if:

•prior to the time that any stockholder became an interested stockholder, the board of directors approved either the business combination or the transaction in which such stockholder acquired 15% or more of our outstanding voting stock; or

•the interested stockholder owns at least 85% of our outstanding voting stock as a result of a transaction in which such stockholder acquired 15% or more of our outstanding voting stock. Shares held by persons who are both directors and officers or by some types of employee stock plans are not counted as outstanding when making this calculation.