Rubicon Technology, Inc. (NASDAQ: RBCN), a leading provider of sapphire substrates and products to the LED, semiconductor and optical markets, today announced the commencement of an underwritten public offering of shares of its common stock by selling stockholders. The offering is subject to customary conditions and there can be no assurance as to whether or when the offering may be completed, or as to the actual size or terms of the offering. In addition, Rubicon expects to grant the underwriters a 30-day option to purchase up to an additional 15 percent of the shares of its common stock offered in the public offering to cover over-allotments, if any. Canaccord Genuity Inc. is acting as sole book-running manager for the offering. Rubicon will not receive any proceeds from the sale of common stock by selling stockholders. The offering is being made pursuant to an effective shelf registration statement previously filed with the Securities and Exchange Commission (SEC). A preliminary prospectus supplement and accompanying prospectus describing the terms of the offering will be filed with the SEC. Any offer, if at all, will be made only by means of a prospectus supplement and accompanying prospectus forming a part of the effective registration statement. Before investing, you should read the prospectus supplement and the accompanying prospectus, and other documents that Rubicon has filed or will file with the SEC, for more complete information about Rubicon and this offering. When available, copies of the preliminary prospectus supplement and accompanying prospectus relating to the offering may be obtained by sending a request to the offices of Canaccord Genuity Inc., Attn: Syndicate Department, 99 High Street, 12th Floor, Boston, MA 02110, or by calling (617) 371-3900. The preliminary prospectus supplement and accompanying prospectus also will be available for free on the SEC's website at www.sec.gov. This press release shall not constitute an offer to sell, or the solicitation of an offer to buy, any of the securities, nor shall there be any sale of these securities, in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state.