GT Advanced Technologies Inc.

Concurrent Offerings of

8,650,000 Shares of Common Stock

(the “Common Stock Offering”)

and
$190 million aggregate principal amount of
3.00% Convertible Senior Notes due 2020
(the “Convertible Senior Notes Offering”)

This information in this pricing term sheet relates to the Common Stock Offering and the Convertible Senior Notes Offering (together, the Offerings) and should be read together, with (i) the preliminary prospectus supplement dated December 2, 2013 (including the documents incorporated by reference therein) relating to the Common Stock Offering (the “Common Stock Preliminary Prospectus Supplement”) and (ii) the preliminary prospectus supplement dated December 2, 2013 (including the documents incorporated by reference therein) relating to the Convertible Senior Notes Offering (the “Convertible Senior Notes Preliminary Prospectus Supplement,” and, together with the Common Stock Preliminary Prospectus, the “Preliminary Prospectus Supplements”) and the accompanying prospectus to each of the Prospectus Supplements dated December 2, 2013 (the “Base Prospectus”). The information in this term sheet supersedes the information in the Preliminary Prospectus Supplements and the Base Prospectus to the extent that it is inconsistent therewith. Terms used but not defined herein have the meanings ascribed to them in the Preliminary Prospectus Supplements.

Changes to Information in the Preliminary Prospectus Supplements

The following changes are made to the information set forth in the applicable Preliminary Prospectus Supplement, and will be reflected in the applicable final prospectus supplement for the applicable Offering.

The following information set forth under the heading “Capitalization” in the applicable Preliminary Prospectus Supplement is updated as follows, and will be reflected in the applicable final prospectus supplement for the applicable Offering:

CAPITALIZATION

The following table sets forth the Issuer’s cash and cash equivalents, current portion of long-term debt and capitalization as of September 28, 2013:

·                                          on an actual basis;

·                                          on an as adjusted basis to reflect (1) the repayment of all amounts outstanding under the Issuer’s senior secured credit facility subsequent to September 28, 2013 but prior to the date hereof, (2) the receipt of the first installment payment of $225 million under the Issuer’s Prepayment Agreement with Apple and (3) receipt of the net proceeds from the sale of the Notes in the Convertible Senior Notes Offering, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Issuer (assuming no exercise of the underwriters’ option to purchase additional Notes). See “Use of Proceeds” in this Free Writing Prospectus and the Preliminary Prospectus Supplements; and

·                                          on an as-further-adjusted basis to reflect the sale of 8,650,000 shares of Common Stock in the Common Stock Offering (assuming no exercise of the underwriters’ option to purchase additional shares) at a public offering price of $8.65 per share, after deducting underwriting discounts and commissions and estimated offering expenses payable by the Issuer.

You should read the following table along with the Issuer’s financial statements and the accompanying notes to those statements and other financial information included in the Preliminary Prospectus Supplements and incorporated therein by reference.

(1)         As adjusted and as further adjusted amounts reflects the repayment of all amounts outstanding under the Issuer’s senior secured credit facility and the associated non-cash charge of approximately $3.6 million related to the write-off of deferred issuance costs.

(2)         Actual amount does not reflect receipt of any portion of the $578 million Prepayment Amount from Apple, which is expected to consist of four payments. As adjusted and as further adjusted amounts reflect receipt of the first installment

payment of $225 million. The Issuer estimates the fair value of the $225 million payment received under the Prepayment Agreement to be $170 million, which reflects that the Prepayment Amount is non-interest bearing. Long-term debt, as adjusted and as further adjusted, reflects the estimated fair value amount of the initial installment payment while the full amount of the initial installment payment is currently reflected in cash and cash equivalents, as adjusted and as further adjusted.

(3)         The as adjusted and as further adjusted carrying amounts of the Notes reflect the issuance proceeds of the Notes, less the estimated discount created by the allocation of a portion of the issuance proceeds related to the conversion feature. The amount allocated to the conversion feature is reflected as additional paid-in capital, which is included in total stockholders’ equity and total capitalization.

(4)         The carrying amount of $165 million is being accreted up to the principal amount of $220 million through October 1, 2017.

(5)         The above table is based on 123.8 million shares of Common Stock outstanding as of September 28, 2013. Such amount does not include: approximately 2.9 million shares of Common Stock issuable upon the exercise of outstanding stock options at a weighted average exercise price of $6.26 per share; approximately 7.7 million shares of Common Stock issuable upon the vesting of restricted stock units; an additional 6.7 million shares of Common Stock available for future issuance as of September 28, 2013 under the Issuer’s equity incentive plans; approximately 28.5 million shares of Common Stock issuable upon the conversion of the Issuer’s 2017 notes and outstanding warrants issued in connection with that offering and the shares of Common Stock to be reserved for issuance upon conversion of the Notes being sold by the Issuer in the Convertible Senior Notes Offering.

Morgan Stanley and Goldman, Sachs & Co. are acting as joint book-running managers for the Common Stock Offering and Convertible Senior Notes Offering. The Issuer has filed a registration statement (including the Preliminary Prospectus Supplements and the Base Prospectus) with the Securities and Exchange Commission, or SEC, for the Common Stock Offering and the Convertible Senior Notes Offering to which this communication relates.  Before you invest, you should read the Preliminary Prospectus Supplements and the Base Prospectus in that registration statement and the other documents the Issuer has filed with the SEC for more complete information about the Issuer, and the Offerings.  You may get these documents for free by visiting EDGAR on the SEC web site at www.sec.gov.  Alternatively, the Issuer, the underwriters or any dealer participating in the Offerings will arrange to send you the Common Stock Preliminary Prospectus Supplement and the Base Prospectus or the Convertible Senior Notes Preliminary Prospectus Supplement and the Base Prospectus if you request them by contacting Morgan Stanley & Co. LLC, Attn: Prospectus Department, 180 Varick Street, 2nd Floor, New York, New York 10014, by calling (866) 718-1649 or by emailing prospectus@morganstanley.com, or from Goldman, Sachs & Co., Attn: Prospectus Department, 200 West Street, New York, NY 10282, by calling 1-866-471-2526 or by emailing prospectus-ny@ny.email.gs.com.

ANY DISCLAIMERS OR OTHER NOTICES THAT MAY APPEAR BELOW ARE NOT APPLICABLE TO THIS COMMUNICATION AND SHOULD BE DISREGARDED. SUCH DISCLAIMERS OR OTHER NOTICES WERE AUTOMATICALLY GENERATED AS A RESULT OF THIS COMMUNICATION BEING SENT VIA BLOOMBERG OR ANOTHER EMAIL SYSTEM.