Page 1

White Mountains INSURANCE GROUP CONTACT : Todd Pozefsky ( 203 ) 458-5807 WHITE MOUNTAINS REPORTS SECOND QUARTER RESULTS HAMILTON , Bermuda ( August 6 , 2021 ) - White Mountains Insurance Group , Ltd. ( NYSE : WTM ) reported book value per share of $ 1,279 and adjusted book value per share of $ 1,292 as of June 30 , 2021. Book value per share and adjusted book value per share both increased 4 % in the second quarter of 2021 and 2 % in the first six months of 2021 , including dividends . Manning Rountree , CEO , commented , “ We had a strong second quarter . Adjusted book value per share was up 4 % , driven by solid results across our operating companies as well as the increase in MediaAlpha's share price during the quarter . BAM produced $ 30 million of total premiums and member surplus contributions , as insured penetration and market share remained strong , while pricing declined . Ark wrote $ 328 million of gross written premiums , up 78 % year over year , and produced an 84 % adjusted combined ratio . NSM generated nice growth in both pro forma controlled premiums and pro forma adjusted EBITDA . Kudu also posted nice growth in adjusted EBITDA and recognized $ 28 million in unrealized gains in the fair value of its portfolio of participation contracts . Excluding MediaAlpha , our investment portfolio returned 2.4 % in the quarter . We finished the second quarter with roughly $ 300 million in undeployed capital . We expect undeployed capital will increase in the third quarter upon completion of the subordinated debt raise at Ark . " Comprehensive income ( loss ) attributable to common shareholders was $ 139 million and $ 66 million in the second quarter and first six months of 2021 , compared to $ 116 million and $ ( 17 ) million in the second quarter and first six months of 2020. Results in the second quarter and first six months of 2021 were driven primarily by $ 113 million and $ 71 million of net realized and unrealized investment gains from White Mountains's investment in MediaAlpha . MediaAlpha White Mountains owns 16.9 million shares of MediaAlpha , representing a 28 % basic ownership interest ( 26 % on a fully - diluted / fully - converted basis ) . At the June 30 closing price of $ 42.10 , the value of White Mountains's investment in MediaAlpha was $ 713 million . At this level of ownership , each $ 1.00 per share increase or decrease in the share price of MediaAlpha will result in an approximate $ 5.50 per share increase or decrease in White Mountains's book value per share and adjusted book value per share . At the July 2021 month - end closing price of $ 33.40 per share , the fair value of White Mountains's investment in MediaAlpha was $ 566 million . 1