X0306 4 2015-02-17 0 0001163348 Allied World Assurance Co Holdings, AG AWH 0001543666 McElroy John Justin ALLIED WORLD ASSURANCE CO. HOLDINGS, AG GUBELSTRASSE 24, PARK TOWER, 15TH FLOOR ZUG V8 6300 SWITZERLAND 0 1 0 0 COO Common Shares 2015-02-17 4 A 0 10980 0.00 A 15172 D Common Shares 2015-02-17 4 F 0 5416 40.24 D 9756 D Common Shares 2015-02-18 4 M 0 1200 0.00 A 10956 D Common Shares 2015-02-18 4 D 0 600 40.4465 D 10356 D Common Shares 2015-02-18 4 F 0 295 40.65 D 10061 D Common Shares 2015-02-19 4 M 0 1434 0.00 A 11495 D Common Shares 2015-02-19 4 D 0 1434 40.5293 D 10061 D Common Shares 76917 I By Trust Restricted Stock Units 2015-02-17 4 A 0 4173 A Common Shares 4173 17535 D Restricted Stock Units 2015-02-18 4 M 0 1200 D Common Shares 1200 16335 D Restricted Stock Units 2015-02-19 4 M 0 1434 D Common Shares 1434 14901 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. 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 4,812 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into (i) 2,406 common shares and (ii) cash equal to the market value of 2,406 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 1,604 Restricted Stock Units converting into (i) 802 common shares and (ii) cash equal to the market value of 802 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 5,739 Restricted Stock Units for no monetary consideration. The Restricted Stock Units convert into cash equal to the market value of 5,739 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 1,913 Restricted Stock Units that convert into cash equal to the market value of the 1,913 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. Represents shares held by a revocable trust for the benefit of the reporting person's children. Grant of Restricted Stock Units for no monetary consideration. Restricted Stock Units convert into (i) 2,504 common shares and (ii) cash equal to the market value of 1,669 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