X0306 4 2015-02-17 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001456268 Gauthier John J ALLIED WORLD ASSURANCE CO. HOLDINGS, AG GUBELSTRASSE 24, PARK TOWER, 15TH FLOOR ZUG V8 6300 SWITZERLAND 0 1 0 0 EVP & CIO Common Shares 2015-02-17 4 A 0 11457 0.00 A 69716 D Common Shares 2015-02-17 4 F 0 5428 40.24 D 64288 D Common Shares 2015-02-18 4 M 0 1662 0.00 A 65950 D Common Shares 2015-02-18 4 D 0 831 40.4465 D 65119 D Common Shares 2015-02-18 4 F 0 393 40.65 D 64726 D Common Shares 2015-02-19 4 M 0 1875 0.00 A 66601 D Common Shares 2015-02-19 4 D 0 1875 40.5293 D 64726 D Restricted Stock Units 2015-02-17 4 A 0 5778 A Common Shares 5778 22494 D Restricted Stock Units 2015-02-18 4 M 0 1662 D Common Shares 1662 20832 D Restricted Stock Units 2015-02-19 4 M 0 1875 D Common Shares 1875 18957 D Represents the Company's common shares that were earned pursuant to a 2012 performance-based award for no monetary consideration and which vested at 136% of target based on the achievement of pre-established performance criteria during the applicable three-year performance period established under the Company's Third Amended and Restated 2004 Stock Incentive Plan. Includes 387 common shares acquired on June 30, 2014 and 278 common shares acquired on December 31, 2014 pursuant to the Company's Amended and Restated 2008 Employee Share Purchase Plan. Reflects the issuer's 3-for-1 stock split paid on May 23, 2014. Exclusively represents shares withheld by the Company with respect to the payment of withholding tax liability incurred upon the vesting of the performance-based awards. On February 18, 2014, the reporting person was granted 6,660 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 3,330 common shares and (ii) cash equal to the market value of 3,330 common shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. These Restricted Stock Units were previously reported as a grant of 2,220 Restricted Stock Units converting into (i) 1,110 common shares and (ii) cash equal to the market value of 1,110 common shares. These amounts have been adjusted to reflect the issuer's 3-for-1 stock split paid on May 23, 2014. The fair market value of the cash portion was determined using the daily volume-weighted average sales price of the common shares for the five consecutive trading days up to and including February 18, 2015. Exclusively represents shares withheld by the Company with respect to the payment of withholding tax liability incurred upon the vesting of Restricted Stock Units. On February 19, 2013, the reporting person was granted 7,503 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into cash equal to the market value of 7,503 common shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. These Restricted Stock Units were previously reported as a grant of 2,501 Restricted Stock Units that convert into cash equal to the market value of the 2,501 common shares. The amount has been adjusted to reflect the issuer's 3-for-1 stock split paid on May 23, 2014. The fair market value was determined using the daily volume-weighted average sales price of the common shares for the five consecutive trading days up to and including February 19, 2015. Grant of Restricted Stock Units for no monetary consideration. Restricted Stock Units convert into (i) 3,467 common shares and (ii) cash equal to the market value of 2,311 common shares (measured at the date of vesting) upon the vesting of such Restricted Stock Units. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 17, 2016. Represents Restricted Stock Units held by the reporting person that vest in whole or in part in cash. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 18, 2015. The Restricted Stock Units vest in four equal installments with the first installment vesting on February 19, 2014. /s/ Wayne H. Datz, by Power of Attorney 2015-02-19