X0306 4 2015-02-17 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001368326 Grossack Marshall J ALLIED WORLD ASSURANCE CO. HOLDINGS, AG GUBELSTRASSE 24, PARK TOWER, 15TH FLOOR ZUG V8 6300 SWITZERLAND 0 1 0 0 EVP, Chief Actuary Common Shares 2015-02-17 4 A 0 9548 0.00 A 216260 D Common Shares 2015-02-17 4 F 0 4451 40.24 D 211809 D Common Shares 2015-02-18 4 M 0 876 0.00 A 212685 D Common Shares 2015-02-18 4 D 0 438 40.4465 D 212247 D Common Shares 2015-02-18 4 F 0 203 40.65 D 212044 D Common Shares 2015-02-19 4 M 0 2208 0.00 A 214252 D Common Shares 2015-02-19 4 D 0 2208 40.5293 D 212044 D Restricted Stock Units 2015-02-17 4 A 0 3050 A Common Shares 3050 17039 D Restricted Stock Units 2015-02-18 4 M 0 876 D Common Shares 876 16163 D Restricted Stock Units 2015-02-19 4 M 0 2208 D Common Shares 2208 13955 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 294 common shares acquired on December 31, 2014 pursuant to the Company's Amended and Restated 2008 Employee Share Purchase Plan. 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 3,516 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 1,758 common shares and (ii) cash equal to the market value of 1,758 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 1,172 Restricted Stock Units converting into (i) 586 common shares and (ii) cash equal to the market value of 586 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 8,829 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into cash equal to the market value of 8,829 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 2,943 Restricted Stock Units that convert into cash equal to the market value of the 2,943 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) 1,830 common shares and (ii) cash equal to the market value of 1,220 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. Reflects the issuer's 3-for-1 stock split paid on May 23, 2014. 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