Presentation to the Board of Directors Project William November 1, 2020

Executive Summary 2 Board began review of strategic alternatives in July 2020Review included broad set of alternatives, including standalone strategy (including possible re-negotiation of agreements with key partners), run-off, and saleWhile strategic review was ongoing, Consortium led by Arthur with two private equity partners approached Company with $25.00 bid on August 16, 2020Arthur a 12.6% holder of William common equity and has 2 board seats; Arthur's directors have recused themselves from all deliberations and votes regarding the Consortium's offerAfter multiple rounds of negotiations, Arthur offered $31.00 per share on October 1, 2020 and subsequently bid $31.10 per share on October 2, 2020Penultimate bid was subject to 24-hour “fuse” and Board determined it incorporated a credible walkaway threatIn order to expedite transaction timing, the two private equity partners are not parties to the acquisition with WilliamDuring the process, Edward also emerged as interested partySubsequent to public rumors of Arthur bid at $26, increased its stake from 5.1% to 9.1% and filed updated 13-DAfter initial outreach, provided bid of $31.00 on September 30, 2020 which was publicly filed; diligence supporting the bid was entirely based on publicly available informationArthur indicated that they would not be inclined to work cooperatively with Edward should Edward acquire WilliamSent follow-up letter on October 5 and filed updated 13-D with letterBoard ultimately elected to pursue Arthur bid at $31.10 on October 2 (Arthur bid on a stand-alone basis, with possible sale of equity interest to other members of the Consortium post-closing)Company signed and announced a definitive merger agreement with Arthur on October 9, with a price of $31.10 per shareEdward sent another public follow-up letter on October 15, providing bid of $34.50 per shareBoard determined that Edward letter might reasonably lead to superior proposal; subsequently granted Edward access to diligence in accordance with the terms of the merger agreementOn October 27, Arthur offered $35.00 per share voting agreement conditioned on reaching an agreement with Edward supporting the transaction at the increased price

Summary of Bid History August 16: Verbal offer from Consortium of $25 per shareAugust 26: Written offer from Consortium of $25 per shareSeptember 3: Verbal offer from Consortium of $27 per shareSeptember 8: Public leak of Consortium interest at $26 per shareSeptember 9: Counteroffer of $32 with $30-34 collar based on performance of non-IG portfolio, with equity rollover electionSeptember 15: Verbal offer from Consortium of $28.25 per shareSeptember 20: Counteroffer of $32 per share with walkaway and hedge structure based on performance of non-IG portfolio, with equity rollover electionSeptember 22: Offer from Consortium of $30 per share with risk share structure with 20% walkaway based on performance of non-IG portfolioSeptember 24: Counterproposals at $31 – both fixed at 36% walkaway and with hedge at 10% walkaway, with equity rollover electionSeptember 26: Offer from Consortium of $30 per share with walkaway at book value (down ~29% in BV)September 29: Counteroffer at $31 per share with walkaway at book valueSeptember 30: Edward offer of $31 per shareBased solely on public information; indicated it would need 2-3 weeks to complete its diligenceIndicated willingness to assume existing contracts, but also a desire to enter into discussions with Arthur and Henry around potential contract terminationFiled its offer letter with updated 13-D on October 1October 1: Arthur offers $31 per share with walkaway at book valueProvided William with 24 hours to accept proposal or Arthur would walk awayIndicated they could reach signed transaction in 3-4 daysSuggested they were not willing to enter into bidding war with Edward, and were not going to facilitate Edward acquisition of WilliamOctober 2: Counteroffer of $32 per share with walkaway at book valueRejected by Arthur; offered price of $31.10 which was ultimately acceptedOctober 5: Edward follow-up letter receivedRequested ability to conduct due diligenceIndicated it may be able to offer a higher price following diligenceOctober 9: Merger Agreement with Arthur signed and announced with price of $31.10 per shareOctober 15: Edward offers $34.50 per shareOctober 16: Board determined Edward offer might lead to superior proposal and granted Edward ability to pursue due diligenceOctober 27: Arthur offers $35 per share; conditioned on reaching an agreement with Edward to vote its shares in favor of Arthur transaction; Edward has not yet agreed, and its agreement will be needed to finalize this deal 3 After initial bid of $25 per share, 7 revised proposals from Arthur, resulting in $35 per share proposal (40% improvement)

Based on Draft Agreement Dated 10/31/2020 4 Summary of Terms Parties to Proposal Arthur Fixed price of $35 per share Termination 12 month termination date with 3 month extension for non-investment grade asset loss conditionArthur can terminate if Board changes its recommendationWilliam can terminate transaction if presented with a superior proposal; William to pay a termination fee of 4.0% Conditions No MAEWilliam shareholder approvalHSR and insurance regulatory approvalsLosses on non-investment grade assets are less than $208MMOther customary conditions Financing Arthur to use available cashClosing not contingent on financing Consideration 100% Cash Purchase Price

Transaction Metrics 5 Implied Transaction Metrics Source: Capital IQ (10/30/2020)Notes:Based on 20.0MM fully diluted shares outstanding as of 06/30/2020, per Company ManagementUnaffected date of 09/08/2020; reflects 52-week trading range prior to unaffected date

Summary of Valuation Analysis Notes:Based on 20.0MM fully diluted shares outstanding as of 6/30/2020, per Company Management; values rounded to nearest $0.25Reflects 52-week trading range prior to unaffected date (09/08/2020)2021E earnings projections based on street consensus as of 10/30/2020Based on Company Management projectionsBased on Company Management projections; terminal multiple range reflects P/BV range of precedent run-off transactions 6 Unaffected Price(09/08/2020):$17.87 Revised Proposal:$35.00 Oct. 9 Merger Agreement:$31.10

Stock Price Performance since Listing Stock Price ($), Volume (MM Shares) Source: Capital IQ (10/30/2020)Notes:1. Period ending 02/19/2020 7 5/14/2020: All-Time Low of $10.86 $36.00 ~140k sharesPre-COVID Average Daily Volume(1) ~65k sharesPost-COVID Average Daily Volume $25.76Listing-to-COVID VWAP(1) $35.00Revised Proposal 9/9/2020 (Leak): $22.309/8/2020 (Unaffected): $17.87 10/29/2019: All-Time High of $28.90 2/19/2020 (COVID): $24.42 ~450k sharesPost-Leak 10/9/2020: Arthur & William announce sale at $31.10 per share 10/15/2020: Edward sends follow-up letter with $34.50 per share bid Post-Leak

William Stock Price Performance vs. Peers Since William Listing 8 Stock Price Performance since William Listing 03/28/2019 – 10/30/2020 (%) Source: Capital IQ (10/30/2020)Notes:Total Return Reinsurance Peers include GLRE and TPRETraditional Reinsurance Peers include ACGL, AXS, RE, RNR and Y +33.3% (8.5%) (32.4%) William Total Return Re. Peers (1) Trad’l Rein. Peers (2) Post-Leak 2/19/2020 (COVID): (10%) Listing-to-Date 9/9/2020 (Leak)Stock price down ~34% pre-leak 10/9/2020: Arthur & William announce sale at $31.10 per share

Trading Multiples: P / BV 01/01/2015 – 10/30/2020 (x) Source: SNL Financial (10/30/2020)Notes:Total Return Reinsurance Peers include GLRE and TPRETraditional Reinsurance Peers include ACGL, AXS, RE, RNR and Y 9 William Total Return Re. Peers (1) Trad’l Rein. Peers (2) Post-Leak 0.83x 0.93x 0.56x William initial listing on 3/28/2019 9/9/2020 (Leak)P/BV (pre-leak): 0.46x 10/9/2020: Arthur & William announce sale at $31.10 per share

Peer Trading Comparables Source: SNL Financial, Capital IQ (10/30/2020), Company FilingsNotes:Reflects median annual combined ratio over the last 10 fiscal years, or since inception as appropriateReflects standard deviation of annual combined ratios over the last 10 fiscal years, or since inception as appropriate Reflects median annual BVPS growth, including dividends, over the last 10 fiscal years, or since inception as appropriateReflects standard deviation of annual BVPS growth, including dividends, over the last 10 fiscal years, or since inception as appropriate 10 (1) (2) (3) (4)

Source: Source: Source: Source: 11 Historical & Projected Financial Highlights Forecasted Financials per Management Projections Premiums Written($MM) ($MM) Combined Ratio (%) Net Investment Assets and Average Yield($MM) ($MM / %) Net Income and ROAE($MM) ($MM / %) (0.3%) 6.0% 2.3% 4.3% 4.1% 4.1% Net Yield: (5.7%) 5.1% 2.1% 9.1% 11.6% 11.0% ROAE: 10.3% 4.1% 14.3% (0.9%) Key Assumptions reflected in Management Projections, per Company Management:Dependent on favorable resolution of potential downgrade from AM BestDependent on Arthur to achieve growth in 2020 business plan and achieve improved combined ratios (although Arthur has expressed concerns about achievability of plan given potential ratings downgrade)Further assumes ongoing market hardening and dependent on no further worsening of macro environment from COVID-19 impactsNo changes to existing agreements with Arthur, based on Arthur declining to amend agreements Source: Company Management

Standalone Dividend Discount Model Summary Based on Company Management Projections Valuation as of 12/31/2020Includes market value gains through 8/31/2020 per Company ManagementBase case financial projections as provided by Company Management Capital target set at 30% BCAR ratioDiscount rate of 10% based on cost of equity analysis(1) Notes:Cost of equity calculated using beta as of unaffected date of 09/08/2020 and current risk-free rate as of 10/30/2020Includes loss reserve equity, senior notes, contingent redeemable preferred shares less intangible assets 12 (2)

Run-Off Analysis - Dividend Discount Model Summary Based on Company Management Projections Valuation as of 12/31/2020Includes market value gains through 8/31/2020 per Company ManagementDiscount rate of 10% based on cost of equity analysis(1)Exit multiple of 0.80x BVPS based on precedent run-off deals(2) Notes:Cost of equity calculated using beta as of unaffected date of 09/08/2020 and current risk-free rate as of 10/30/2020Terminal multiple range reflects P/BV range of precedent run-off transactions; 0.80x reflects midpoint of rangeBased on 50% of net reserves 13 (3) (2)

Precedent Transactions Run-Off Transactions – P&C Source: Capital IQ, SNL Financial, Company Filings and Materials 14 Notes:Deal value and multiples based on the combined value and book value of Downlands Liability Management and Hartford Financial Products International Limited (1)

Premiums Paid for U.S. Public Targets (1)(2) Transactions of $100MM or More All Cash Consideration 25-Year Avg: 38.3% S&P 500 (3) Source: Source: 15 Notes:Includes announced bids for control of U.S. public targets with an aggregate value of $100MM or more; excludes terminated transactions, ESOPs, self-tenders, spin-offs, share repurchases, minority interest transactions, exchange offers, recapitalizations, and restructurings. Includes transactions announced on or before 06/30/2020Annual amounts based on mean of percentage premiums paid over unaffected stock price which is defined as stock price four weeks prior to the earliest of the deal announcement; announcement of a competing bid; and market rumorsS&P 500 indexed to closing price on the last trading day of 1996 Source: Refinitiv (06/30/2020)

16 Cost of Equity Analysis: CAPM Method William Cost of Equity Analysis Source: Capital IQ, SNL Financial (beta as of unaffected date of 09/08/2020, current risk-free rate as of 10/30/2020) Peer Levered Betas:GLRE:1.19TPRE:1.25Average: 1.22

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