liabilities, subject to the prior rights of any holders of preferred stock then outstanding. The holders of common stock have no other preemptive, subscription, redemption, sinking fund or
conversion rights. All outstanding shares of our common stock are fully paid and nonassessable. The shares of common stock to be issued upon closing of an offering will also be fully paid and nonassessable. The rights, preferences and privileges of
holders of common stock are subject to, and may be negatively impacted by, the rights of the holders of shares of any series of preferred stock which we may designate and issue in the future.
As of March 31, 2019, 52,994,050 shares of our common stock were outstanding.
As of March 31, 2019, options to purchase 6,631,328 shares of our common stock at a weighted average exercise price of $44.68 per share
were outstanding.
As of March 31, 2019, 2,607,982 shares of our common stock were issuable upon the vesting of restricted stock
units outstanding.
As of March 31, 2019, 4,646,460 shares were issuable upon conversion of our 2.50% Convertible Senior Notes due
2021, and 3,938,340 shares were issuable upon the conversion of our 1.25% Convertible Senior Notes due 2025.
Undesignated Preferred Stock
Under our amended and restated certificate of incorporation, our board of directors has the authority, without action by our stockholders, to
designate and issue up to 10 million shares of preferred stock in one or more series and to designate the rights, preferences and privileges of each series, any or all of which may be greater than the rights of our common stock. It is not
possible to state the actual effect of the issuance of any shares of preferred stock upon the rights of holders of our common stock until our board of directors determines the specific rights of the holders of preferred stock. However, the effects
might include, among other things, restricting dividends on the common stock, diluting the voting power of the common stock, impairing the liquidation rights of the common stock and delaying or preventing a change in control of our common stock
without further action by our stockholders and may adversely affect the market price of our common stock. As of May 31, 2019, no shares of our preferred stock were outstanding.
Registration Rights
The selling
stockholder is entitled to rights with respect to the registration under the Securities Act of the resale of the shares received by it in connection with the settlement of the Antipodean matter. Registration of the resale of these shares under the
Securities Act would result in the shares becoming freely tradable without restriction under the Securities Act. The settlement agreement required us to file the registration statement of which this prospectus forms a part covering the resale of the
shares received by the selling stockholder in the settlement. We are obligated to use reasonable best efforts to cause the registration statement to be declared effective by the SEC as promptly as practicable and to keep the registration statement
effective until the earliest of (i) when the selling stockholder has sold or otherwise transferred its shares received in the settlement, (ii) the first day when the selling stockholder is able to sell all of its shares received in the
settlement pursuant to Rule 144 under the Securities Act and (iii) the
one-year
anniversary of the date the shares were issued to Antipodean under the settlement agreement. Any sales of securities by the
selling stockholder could have a material adverse effect on the trading price of our common stock.
Anti-Takeover Provisions of Delaware Law
We are subject to Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly held Delaware
corporation from engaging in a business combination with an interested stockholder for a period of three years following the date the person became an interested stockholder, unless the business
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