Description of Registrants Securities

The following description of the capital stock of BlackLine, Inc. (“us,” “our,” “we” or the “Company”) is a summary of the rights of our common stock and certain provisions of our amended and restated certificate of incorporation and amended and restated bylaws currently in effect. This summary does not purport to be complete and is qualified in its entirety by the provisions of our amended and restated certificate of incorporation and amended and restated bylaws, each as filed or incorporated by reference as an exhibit to the Annual Report on Form 10-K of which this Exhibit 4.2 is a part, as well as to the applicable provisions of the Delaware General Corporation Law (the “DGCL”). For a complete description of our capital stock, we encourage you to read our certificate of incorporation, bylaws and the applicable portions of the DGCL carefully.

Our authorized capital stock consists of 500,000,000 shares of common stock, $0.01 par value and 50,000,000 shares of preferred stock, $0.01 par value.

Each holder of our common stock is entitled to one vote for each share on all matters submitted to a vote of the stockholders, including the election of directors. Under our amended and restated certificate of incorporation and bylaws, our stockholders will not have cumulative voting rights. Because of this, the holders of a majority of the shares of common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they should so choose.

Holders of common stock are entitled to receive ratably those dividends, if any, as may be declared from time to time by the board of directors out of legally available funds.

In the event of our liquidation, dissolution or winding up, holders of common stock will be entitled to share ratably in the net assets legally available for distribution to stockholders after the payment of all of our debts and other liabilities.

Holders of shares of common stock have no preemptive, conversion or subscription rights and there are no redemption or sinking fund provisions applicable to the common stock. The rights, preferences and privileges of the holders of shares of 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 in the future.

No shares of our preferred stock are currently outstanding. Under our amended and restated certificate of incorporation, our board of directors, without further action by our stockholders, is authorized to issue shares of preferred stock in one or more classes or series. The board may fix or alter the rights, preferences and privileges of the preferred stock, along with any limitations or restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences of each class or series of preferred stock. The preferred stock could have voting or conversion rights that could adversely affect the voting power or other rights of holders of our common stock. The issuance of preferred stock could also have the effect, under certain circumstances, of delaying, deferring or preventing a change of control of the Company. We currently have no plans to issue any shares of preferred stock.

Certain provisions of Delaware law, our amended and restated certificate of incorporation and our amended and restated bylaws contain provisions that could have the effect of delaying, deferring or discouraging another party from acquiring control of us. These provisions are also designed, in part, to encourage persons seeking to acquire

control of us to negotiate first with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate more favorable terms with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire us.

Our amended and restated certificate of incorporation provides that our board of directors is divided into three classes of directors, with the classes as nearly equal in number as possible, and with the directors serving three-year terms. As a result, approximately one-third of our board will be elected each year. The classification of directors will have the effect of making it more difficult for stockholders to change the composition of our board. Our amended and restated certificate of incorporation also provides that, subject to any rights of holders of preferred stock to elect additional directors under specified circumstances and the Stockholders’ Agreement by and between the Company and our principal stockholders named therein (“Principal Stockholders”), dated as of October 27, 2016 (the “Stockholders’ Agreement”), the number of directors will be fixed exclusively pursuant to a resolution adopted by our board.

Our amended and restated certificate of incorporation precludes stockholder action by written consent.

Our amended and restated certificate of incorporation provides that, except as required by law, special meetings of our stockholders may be called at any time only by or at the direction of our board or the chairman of our board. Our amended and restated bylaws prohibit the conduct of any business at a special meeting other than as specified in the notice for such meeting. These provisions may have the effect of deferring, delaying or discouraging hostile takeovers, or changes in control or management of the Company.

Our amended and restated bylaws contain an advance notice procedure for stockholder proposals to be brought before an annual meeting of our stockholders, including proposed nominations of persons for election to our board; provided, however, such advance notice procedures will not apply to a Principal Stockholder at any time when such Principal Stockholder beneficially owns at least 10% of the total number of shares of our common stock then outstanding. 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 or by a stockholder who was a stockholder of record on the record date for the meeting, who is entitled to vote at the meeting and who has given our secretary timely written notice, in proper form, of the stockholder’s intention to bring that business before the meeting. Although the amended and restated bylaws will not give our board the power to approve or disapprove stockholder nominations of candidates or proposals regarding other business to be conducted at a special or annual meeting, the bylaws may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed or may discourage or deter a potential acquirer from conducting a solicitation of proxies to elect its own slate of directors or otherwise attempting to obtain control of the Company.

Our amended and restated certificate of incorporation provides that directors may be removed with or without cause upon the affirmative vote of a majority in voting power of all outstanding shares of stock entitled to vote thereon, voting together as a single class. In connection with votes for removal, the parties to the Stockholders’ Agreement will agree to vote their shares in accordance with the board composition requirements in such agreement and the wishes of the party which designated a director regarding removal of such director. Any newly created directorships that result in a vacancy on the board will be filled by a majority of the directors then in office, even if less than a quorum, or by a sole remaining director (and not by the stockholders). In addition, in the event that Therese Tucker ceases to be employed by the Company for any reason and she owns less than 5% of the total number of shares of our common stock outstanding, (i) she will be required to immediately tender her resignation from the board of directors effective only upon acceptance by the board of directors and (ii) the board of directors may, in its sole discretion, accept or reject such resignation. If the board of directors rejects the resignation, Ms. Tucker will continue to have the right to be designated for membership on the board of directors; provided that the board of directors will have the right, by unanimous vote of the other directors (excluding Ms. Tucker), to require

such director’s resignation from the board of directors if the board of directors determines such resignation would be in the best interests of the Company, regardless of the number of shares of common stock held by Ms. Tucker.

Our amended and restated certificate of incorporation and amended and restated bylaws provide that our board of directors is expressly authorized to make, alter, amend and rescind, in whole or in part, our bylaws without a stockholder vote in any matter not inconsistent with the laws of the State of Delaware and our certificate of incorporation. Any amendment, alteration, rescission or repeal of our amended and restated bylaws by our stockholders requires the affirmative vote of the holders of at least 75% voting power of all the then outstanding shares of our stock entitled to vote thereon, voting together as a single class.

The DGCL provides generally that the affirmative vote of a majority of the outstanding shares entitled to vote thereon, voting together as a single class, is required to amend a corporation’s certificate of incorporation, unless the certificate of incorporation requires a greater percentage.

Our certificate of incorporation provides that, the following provisions in our amended and restated certificate of incorporation may be amended, altered, repealed or rescinded only by the affirmative vote of the holders of at least 75% of the voting power of all the then outstanding shares of our stock entitled to vote thereon, voting together as a single class:

•the provisions providing for a classified board of directors (the election and term of our directors);

•the provisions regarding resignation and removal of directors;

•the provisions regarding competition and corporate opportunity;

•the provisions regarding entering into business combinations with interested stockholders;

•the provisions regarding stockholder action by written consent;

•the provisions regarding calling special meetings of stockholders;

•the provisions regarding filling vacancies on our board and newly created directorships;

•the provisions eliminating monetary damages for breaches of fiduciary duty by a director; and

•the amendment provision requiring that the above provisions be amended only with a 75% supermajority vote.

The combination of the classification of our board of directors, the lack of cumulative voting and the supermajority voting requirements will make it more difficult for our existing stockholders to replace our board of directors as well as for another party to obtain control of us by replacing our board. Because our board of directors has the power to retain and discharge our officers, these provisions could also make it more difficult for existing stockholders or another party to effect a change in management.

Our authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval, subject to stock exchange rules. 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. One of the effects of the existence of authorized but unissued common stock or preferred stock may be to enable our board to issue shares to persons friendly to current management, which issuance could render more difficult or discourage an attempt to obtain control of the Company by means of a merger, tender offer, proxy contest or otherwise, and thereby protect the continuity of our management and possibly deprive our stockholders of opportunities to sell their shares of common stock at prices higher than prevailing market prices.

We are not subject to the provisions of Section 203 of the DGCL. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that the person becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions: (1) before the stockholder became an interested stockholder, the board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder; (2) upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances; or (3) at or after the time the stockholder became an interested stockholder, the business combination was approved by the board of directors and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least two-thirds of the outstanding voting stock which is not owned by the interested stockholder.

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its certificate of incorporation or bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares.

We have opted out of Section 203; however, our amended and restated certificate of incorporation contains similar provisions providing that we may not engage in certain “business combinations” with any “interested stockholder” for a three-year period following the time that the stockholder became an interested stockholder, unless:

•prior to such time, our board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

•upon consummation of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of our voting stock outstanding at the time the transaction commenced, excluding certain shares; or

•at or subsequent to that time, the business combination is approved by our board of directors and by the affirmative vote of holders of at least 66 2/3% of our outstanding voting stock that is not owned by the interested stockholder.

Under certain circumstances, this provision will make it more difficult for a person who would be an “interested stockholder” to effect various business combinations with the Company for a three-year period. This provision may encourage companies interested in acquiring the Company to negotiate in advance with our board because the stockholder approval requirement would be avoided if our board approves either the business combination or the transaction which results in the stockholder becoming an interested stockholder. These provisions also may have the effect of preventing changes in our board and may make it more difficult to accomplish transactions which stockholders may otherwise deem to be in their best interests.

Our Our amended and restated bylaws provide that, unless we consent in writing to the selection of an alternative forum, the sole and exclusive forum for (1) any derivative action or proceeding brought on our behalf, (2) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, stockholders or other employees to us or our stockholders, (3) any action asserting a claim against the Company or any director or officer of the Company arising pursuant to any provision of the DGCL or our certificate of incorporation or bylaws, or (4) any other action asserting a claim that is governed by the internal affairs doctrine shall be the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, another State court in Delaware or the federal district court for the District of Delaware), in all cases subject to the court’s having jurisdiction over the claims at issue and the indispensable parties; provided that the exclusive forum provision will not apply to suits brought to enforce any liability or duty created by the Exchange Act. Our amended and restated bylaws further provide that, unless we consent in writing to the selection of an alternative forum, the federal district courts of the United States of America will be the sole and exclusive forum for resolving any complaints or asserting any cause of action arising under the Securities Act.

Any person or entity purchasing, holding or otherwise acquiring any interest in our securities shall be deemed to have notice of and consented to this provision. The exclusive forum provisions may limit a stockholder's ability to bring a claim in a judicial forum of its choosing for disputes with us or any of our directors, officers, or other employees, which may have the effect of discouraging lawsuits against us or our directors and officers.

The DGCL authorizes corporations to limit or eliminate the personal liability of directors to corporations and their stockholders for monetary damages for breaches of directors’ fiduciary duties, subject to certain exceptions. Our amended and restated certificate of incorporation includes a provision that eliminates the personal liability of directors for monetary damages for any breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted under the DGCL. These provisions eliminate the rights of us and our stockholders, through stockholders’ derivative suits on our behalf, to recover monetary damages from a director for breach of fiduciary duty as a director, including breaches resulting from grossly negligent behavior. However, exculpation will not apply to any director if the director has acted in bad faith, knowingly or intentionally violated the law, authorized illegal dividends or redemptions or derived an improper benefit from his or her actions as a director.

Our amended and restated bylaws provide that we must indemnify and advance expenses to our directors and officers to the fullest extent authorized by the DGCL. We also are expressly authorized to carry directors’ and officers’ liability insurance providing indemnification for our directors, officers and certain employees for some liabilities. We believe that these indemnification and advancement provisions and insurance will be useful to attract and retain qualified directors and officers.

The limitation of liability, indemnification and advancement provisions included in our certificate of incorporation and bylaws may discourage stockholders from bringing a lawsuit against directors for breaches of their fiduciary duty. These provisions also may have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit us and our stockholders. In addition, your investment may be adversely affected to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions.

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC. The transfer agent and registrar’s address is 6201 15th Avenue, Brooklyn, New York 11219.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “BL”.