Stockholders' Equity	9 Months Ended
Sep. 30, 2019
Equity [Abstract]
STOCKHOLDERS' EQUITY	5. STOCKHOLDERS' EQUITY Common shares reserved As of September 30, 2019, the Company had reserved 77,842 shares of common stock for issuance upon the exercise of outstanding common stock options and vesting of RSUs. Also, 280,386 shares of the Company's common stock were reserved for future grants of stock options and RSUs (or other similar equity instruments) under the Rubicon Technology, Inc. 2016 Stock Incentive Plan (the "2016 Plan") as of September 30, 2019. Preferred stock At the Company's 2018 annual meeting ("2018 Annual Meeting") of stockholders, an amendment to the Company's Eighth Amended and Restated Certificate of Incorporation (as amended, the "Certificate of Incorporation") was approved to decrease the Company's authorized number of shares of preferred stock from 5,000,000 shares to 1,000,000 shares. Subsequent to receiving stockholder approval at the 2018 Annual Meeting, the Company filed with the Secretary of State of the State of Delaware a Certificate of Amendment to decrease the authorized number of preferred shares, consequently reducing the number of total authorized shares from 13,200,000 to 9,200,000.

Stockholders' Equity

9 Months Ended

Sep. 30, 2019

5. STOCKHOLDERS' EQUITY

Common shares reserved

As of September 30, 2019, the Company had reserved 77,842 shares of common stock for issuance upon the exercise of outstanding common stock options and vesting of RSUs. Also, 280,386 shares of the Company's common stock were reserved for future grants of stock options and RSUs (or other similar equity instruments) under the Rubicon Technology, Inc. 2016 Stock Incentive Plan (the "2016 Plan") as of September 30, 2019.

Preferred stock

At the Company's 2018 annual meeting ("2018 Annual Meeting") of stockholders, an amendment to the Company's Eighth Amended and Restated Certificate of Incorporation (as amended, the "Certificate of Incorporation") was approved to decrease the Company's authorized number of shares of preferred stock from 5,000,000 shares to 1,000,000 shares. Subsequent to receiving stockholder approval at the 2018 Annual Meeting, the Company filed with the Secretary of State of the State of Delaware a Certificate of Amendment to decrease the authorized number of preferred shares, consequently reducing the number of total authorized shares from 13,200,000 to 9,200,000.