SELECTIVE INSURANCE GROUP INC

Insurance Operations

The following table provides quantitative information for analyzing the combined ratio:

The NPW growth of 13% in Second Quarter 2024 and 14% in Six Months 2024 compared to the same prior-year periods reflected (i) overall renewal pure price increases, and (ii) higher direct new business, as shown in the following table:

Our NPW growth in Second Quarter 2024 and Six Months 2024 also benefited from stable retention and exposure growth on renewal policies.

Loss and Loss Expenses

The loss and loss expense ratio increased 17.1 points in Second Quarter 2024 and 10.7 points in Six Months 2024 compared to the same prior-year periods, primarily due to the following:

Details of the prior year casualty reserve development were as follows:

The unfavorable prior year casualty reserve development of (i) $166.0 million in Second Quarter 2024 and $216.0 million in Six Months 2024 in our general liability line of business was driven by severities in accident years 2020 through 2023 that continued to show higher emergence than expected, and (ii) $10.0 million in Second Quarter 2024 in our commercial automobile line of business was driven by increased severities in accident year 2023. The unfavorable development in Six Months 2024 was partially offset by favorable workers compensation development of $15.0 million. For additional qualitative discussion on prior year casualty reserve development, refer to the insurance segment sections below.

In addition, the loss and loss expense ratio was adversely impacted by an increase in current year casualty loss costs of 2.1 points in Second Quarter 2024 and 1.3 points in Six Months 2024, compared to the same prior-year periods, primarily due to increased loss trend expectations and higher prior-year severity assumptions attributable to social inflationary impacts in our general liability line of business.

Net catastrophe losses were lower in Second Quarter 2024 and Six Months 2024 compared to the same prior-year periods, but remain higher than our historical average. Severe convective storms across our footprint drove our catastrophe losses in the quarter.

Underwriting Expenses

The underwriting expense ratio decreased 1.1 points in Second Quarter 2024 and 1.4 points in Six Months 2024 compared to the same prior-year periods, primarily due to a decrease in profit-based compensation to our employees and distribution partners, coupled with premium growth outpacing the growth in underwriting expenses.

Standard Commercial Lines Segment

NPW growth of 11% in Second Quarter 2024 and 13% in Six Months 2024 compared to the same prior-year periods reflected (i) renewal pure price increases, (ii) higher direct new business, and (iii) strong retention as shown in the table below. In addition, NPW growth benefited from strong exposure growth on renewal policies.

The loss and loss expense ratio increased 22.6 points in Second Quarter 2024 and 14.1 points in Six Months 2024 compared to the same prior-year periods, primarily driven by the following:

Prior year casualty reserve development was unfavorable by $176.0 million, or 20.6 points, in Second Quarter 2024, compared to $7.5 million, or 1.0 point, of favorable development in Second Quarter 2023. Prior year casualty reserve development was unfavorable by $211.0 million, or 12.5 points, in Six Months 2024, compared to $17.5 million, or 1.2 points, of favorable development in Six Months 2023.

Despite increasing our expected loss trend in recent years, loss severities continued to show higher emergence than expected in Second Quarter 2024 and Six Months 2024 in the general liability line of business. In response to these unfavorable trends, we recorded unfavorable prior year casualty reserve development in our general liability line of business of $166.0 million in Second Quarter 2024 and $216.0 million in Six Months 2024, primarily driven by increased severities in accident years 2020 through 2023. In addition, we recorded $10.0 million of unfavorable prior year casualty reserve development in our commercial automobile line of business in Second Quarter 2024 and Six Months 2024, primarily driven by increased severities in accident year 2023. The unfavorable development in Six Months 2024 was partially offset by $15.0 million of favorable workers compensation development.

In addition, the loss and loss expense ratio was adversely impacted by an increase in current year casualty loss costs of 3.4 points in Second Quarter 2024 and 2.1 points in Six Months 2024 compared to the same prior-year periods, primarily due to increased loss trend expectations and higher prior-year severity assumptions attributable to impacts from social inflation in the general liability line of business.

Refer to the line of business sections below for qualitative discussion on the significant drivers of unfavorable prior year casualty reserve development and current year loss costs.

The underwriting expense ratio decreased 0.8 points in Second Quarter 2024 and 1.2 points in Six Months 2024 compared to the same prior-year periods, primarily due to a decrease in profit-based compensation to our employees and distribution partners, coupled with premium growth outpacing the growth in underwriting expenses.

The following is a discussion of our most significant Standard Commercial Lines of business:

NPW grew 9% in Second Quarter 2024 and 11% in Six Months 2024 compared to the same prior-year periods, benefiting from renewal pure price increases, exposure growth on renewal policies, strong retention, and higher direct new business.

The combined ratio increased 72.1 points in Second Quarter 2024 and 47.3 points in Six Months 2024 compared to the same prior-year periods, primarily driven by unfavorable prior year casualty reserve development as follows:

This line of business has experienced a long-term historical trend of meaningful severity increases, which have been partially offset by decreases in claim frequencies. Prior-year severities have developed adversely, previously impacting the pre-pandemic period but now extending into the more recent accident years. We attribute the increased severities to elevated social inflation, which we see as an industry dynamic characterized by higher propensity for attorney representation and litigation, longer settlement times, and higher settlement values. Certain jurisdictions with expanded liability theories and higher damage awards pose heightened challenges. We are closely monitoring these jurisdictions and the broader trends across our business.

The unfavorable prior year casualty reserve development in Second Quarter 2024 and Six Months 2024 was primarily due to the impact of social inflation, which resulted in higher severity assumptions embedded in our initial loss ratio estimates in recent years. Despite planning for higher expected loss trends, claim emergence in Second Quarter 2024 and Six Months 2024 continued to exceed our expectations. In response to these continued unfavorable trends, we recorded unfavorable prior year development of $166.0 million in Second Quarter 2024 and $216.0 million in Six Months 2024, primarily in accident years 2020 through 2023. There was no prior year casualty reserve development in Second Quarter 2023 and Six Months 2023.

Additionally, the combined ratio was adversely impacted by an increase in current year casualty loss costs of 13.6 points in Second Quarter 2024 and 9.0 points in Six Months 2024 compared to the same prior-year periods, primarily driven by an increase to our loss trend expectations and higher prior-year severity assumptions attributable to increases in social inflationary impacts.

We believe that social inflation and elevated loss trends are an industry dynamic, and may lead to an acceleration of rate increases in this line of business for the industry and us. Our renewal pure price increase in this line of business was 7.6% in Second Quarter 2024, up from 6.5% last quarter, and 5.7% for the fourth quarter of 2023. We expect increases in our general liability pricing to accelerate in the coming months.

Partially offsetting the unfavorable combined ratio drivers mentioned above was a decrease in the underwriting expense ratio of 0.6 points in Second Quarter 2024 and 0.9 points in Six Months 2024 compared to the same prior-year periods, as discussed in the "Standard Commercial Lines Segment" section above.

NPW grew 16% in Second Quarter 2024 and 17% in Six Months 2024 compared to the same prior-year periods, benefiting from renewal pure price increases, higher direct new business, and strong retention. This higher new business and strong retention contributed to an 8% growth of in-force vehicle counts as of June 30, 2024 compared to June 30, 2023.

The combined ratio decreased 1.4 points in Second Quarter 2024 and 3.4 points in Six Months 2024 compared to the same prior-year periods, and included the following:

Non-catastrophe property loss and loss expenses in Second Quarter 2024 and Six Months 2024 were lower compared to the same prior-year periods, primarily due to lower claim frequencies.

In addition, the combined ratio was reduced by the following:

•Decreases in current year casualty loss costs of 1.3 points in Second Quarter 2024 and 1.2 points in Six Months 2024 compared to the same prior-year periods, primarily driven by the earned impact of higher renewal pure price increases in both periods as highlighted above; and

•Decreases in the underwriting expense ratio of 0.3 points in Second Quarter 2024 and 0.7 points in Six Months 2024 compared to the same prior-year periods, as discussed in the "Standard Commercial Lines Segment" section above.

Offsetting the favorable combined ratio drivers mentioned above, was unfavorable prior year casualty reserve development in Second Quarter 2024 and Six Months 2024, primarily due to increased severities in accident year 2023. There was no prior year casualty reserve development in Second Quarter 2023 and Six Months 2023.

1 includes Inland Marine.

2 n/a: not applicable.

NPW grew 17% in Second Quarter 2024 and 16% in Six Months 2024 compared to the same prior-year periods, benefiting from renewal pure price increases, strong retention, exposure growth on renewal policies, and higher direct new business.

The combined ratio decreased 15.5 points in Second Quarter 2024 and 7.2 points in Six Months 2024 compared to the same prior-year periods, primarily driven by lower net catastrophe losses as shown in the following table:

Net catastrophe losses in Second Quarter 2024 and Six Months 2024 were lower compared to the same prior-year periods, but remain higher than our historical average.

In addition, the combined ratio was favorably impacted by a decrease in the underwriting expense ratio of 2.5 points in Second Quarter 2024 and 2.6 points in Six Months 2024 compared to the same prior-year periods, as discussed in the "Standard Commercial Lines Segment" section above.

Offsetting the favorable combined ratio drivers mentioned above, was higher non-catastrophe property loss and loss expense ratios in Second Quarter 2024 and Six Months 2024 compared to the same prior-year periods. This change continues to reflect the variability from period to period that is normally associated with the commercial property line of business. We continue to manage our long-term profitability through (i) price increases, and (ii) targeted underwriting actions, including an ongoing focus on appropriate policy terms and conditions and achieving accurate insurance-to-value ratios.

NPW decreased 11% in Second Quarter 2024 and 3% in Six Months 2024 compared to the same prior-year periods, primarily due to renewal pure price decreases and a reduction in direct new business.

The combined ratio increased 9.5 points in Second Quarter 2024 and 2.7 points in Six Months 2024 compared to the same prior-year periods, primarily driven by reductions in favorable prior year casualty reserve development as follows:

The favorable prior year casualty reserve development in Six Months 2024 was primarily due to lower loss severities in accident years 2021 and prior. The favorable prior year casualty reserve development in Second Quarter 2023 and Six Months 2023 was primarily due to improved loss severities in accident years 2020 and prior.

In addition, the combined ratio was adversely impacted by an increase in current year casualty loss costs of 2.8 points in Second Quarter 2024 and 3.1 points in Six Months 2024, primarily driven by the negative rate environment that has been impacting this line for several years.

Offsetting the unfavorable combined ratio drivers mentioned above was a decrease in the underwriting expense ratio of 0.8 points in Second Quarter 2024 and 1.0 point in Six Months 2024 compared to the same prior-year periods, as discussed in the "Standard Commercial Lines Segment" section above.

Standard Personal Lines Segment

NPW increased 6% in Second Quarter 2024 and 11% in Six Months 2024 compared to the same prior-year periods, due to renewal pure price increases, exposure growth on renewal policies, and higher average policy sizes from our mass affluent market strategy, partially offset by reductions in direct new business and retention. New policy counts were down 48% in Second Quarter 2024 and 43% in Six Months 2024 compared to the same prior-year periods. These reductions were anticipated given the level of rate increases we are implementing as part of our overall profit improvement plan.

1 Excludes our Flood direct premiums written, which is 100% ceded to the NFIP and therefore, has no impact on our NPW.

We are taking aggressive actions to improve the profitability of this business by continuing to prioritize additional rate filings on a state-by-state basis to mitigate inflationary impacts, and refining our pricing factors. These filed rate increases began to take effect early in 2023, increasing in number and magnitude throughout 2023, have continued into 2024, and are expected to continue throughout the year. We achieved a 20.7% renewal pure price increase in Second Quarter 2024, a direct outcome of these actions. In addition, we are seeking to further improve profitability within our homeowners' line of business by introducing new policy terms and conditions, including (i) coverage for older roofs based on a schedule of factors rather than replacement cost, and (ii) implementing mandatory wind/hail deductibles in states exposed to severe convective storms, where allowed by law.

The loss and loss expense ratio decreased 5.7 points in Second Quarter 2024 and 7.1 points in Six Months 2024 compared to the same prior-year periods, driven by the following:

In Six Months 2024, we experienced (i) favorable prior year casualty reserve development on our homeowners line of business of $5.0 million, primarily due to lower loss severities in accident years 2021 and prior, offset by (ii) $5.0 million of unfavorable prior year casualty reserve development on our personal automobile line of business, primarily driven by increased loss severities in accident years 2021 through 2023. The unfavorable prior year casualty reserve development in Second Quarter 2023 and Six Months 2023 was primarily due to increased loss severities in accident year 2022 on our personal automobile line of business.

In addition, lower net catastrophe losses in Second Quarter 2024 and Six Months 2024 compared to the same prior-year periods lowered our loss and loss expense ratio, but net catastrophe losses remain higher than our historical average.

The loss and loss expense ratio was also adversely impacted by a 1.0-point increase in current year casualty loss costs in Six Months 2024 compared to Six Months 2023, primarily due to an expected increase in automobile claim frequencies in the current year.

The underwriting expense ratio decreased 2.7 points in Second Quarter 2024 and 2.6 points in Six Months 2024 compared to the same prior-year periods, primarily due to a decrease in profit-based compensation to our employees and distribution partners, coupled with premium growth outpacing the growth in underwriting expenses in both periods.

E&S Lines Segment

NPW grew 39% in Second Quarter 2024 and 31% in Six Months 2024 compared to the same prior-year periods, reflecting renewal pure price increases and higher direct new business as shown in the table below. In addition, NPW growth in Second Quarter 2024 and Six Months 2024 benefited from both property and casualty exposure growth on renewal policies, driven by higher rate per exposure and higher new business production. In addition, our property lines exposure growth on renewal policies was reflective of increased property values.

The loss and loss expense ratio decreased 4.6 points in Second Quarter 2024 and 0.4 points in Six Months 2024 compared to the same prior-year periods, and included the following:

While the frequency of wind and thunderstorm events remained largely consistent, the severity of these events was lower in Second Quarter 2024 and Six Months 2024 compared to the same prior-year periods, resulting in a decrease in net catastrophe losses in both periods.

In addition, the loss and loss expense ratio was favorably impacted by a decrease in current year casualty loss costs of 3.1 points in Second Quarter 2024 and 2.7 points in Six Months 2024 compared to the same prior-year periods, primarily due to the mix of business between our property and casualty lines of business. Our E&S property line of business, which has a lower loss ratio compared to our E&S casualty line of business, represented a larger portion of this segment in Second Quarter 2024 and Six

Months 2024 compared to the same prior-year periods, resulting in a lower blended current year loss cost in Second Quarter 2024 and Six Months 2024.

These decreases to the loss and loss expense ratio were offset by the following:

•Higher non-catastrophe property loss and loss expenses in Second Quarter 2024 and Six Months 2024 compared to the same prior-year periods, primarily due to several large fires, reflecting the continued variability from period to period that is normally associated with our E&S property line of business; and

•No prior year casualty reserve development in Second Quarter 2024 and Six Months 2024 compared to favorable prior year casualty reserve development in Six Months 2023. The 2023 development was primarily due to lower severities in accident years 2021 and prior.

The decrease in the underwriting expense ratio of 1.5 points in Second Quarter 2024 and 1.4 points in Six Months 2024 compared to the same prior-year periods, was primarily due to premium growth outpacing the growth in underwriting expenses in both periods.

Reinsurance

We successfully completed negotiations of our July 1, 2024 excess of loss treaties, which cover our Standard Commercial Lines, Standard Personal Lines, and E&S Lines.

We renewed the Casualty Excess of Loss Treaty ("Casualty Treaty") with substantially the same structure as the expiring treaty with a co-participation of 17.5% on the first $3 million in excess of $2 million layer, but with the benefit of additional reinstatements on several of the layers. The treaty year 2024 deposit premium increased, reflecting (i) higher projected subject earned premium due to growth in our book of business, including pure renewal rate increases; and (ii) higher anticipated losses in the excess layers, partially offset by (iii) the introduction of the first layer co-participation.

We renewed the Property Excess of Loss Treaty (“Property Treaty”) with substantially the same structure as the expiring treaty and an additional reinstatement on the second layer of the program. The treaty year deposit premium increased, reflecting higher projected subject earned premium due to growth in our book of business.

The following table summarizes the Property Treaty and Casualty Treaty arrangements covering our Insurance Subsidiaries:

Investments

Our investment portfolio's objectives are to maximize after-tax net investment income and generate long-term growth in book value per share by maximizing the overall total return of the portfolio by investing the premiums we receive from our insurance operations and the amounts generated through our capital management strategies, which may include debt and equity security issuances. We balance those objectives against prevailing market conditions, capital preservation considerations, and our enterprise risk-taking appetite. We maintain (i) a well-diversified portfolio across issuers, sectors, and asset classes and (ii) a high credit quality fixed income securities portfolio with a duration and maturity profile at an acceptable risk level that provides ample liquidity.

The effective duration of our fixed income and short-term investments was 3.9 years as of June 30, 2024. The effective duration is monitored and managed to maximize yield while managing interest rate risk at an acceptable level. Purchases and sales are made with the intent of maximizing investment returns in the current market environment, while balancing capital preservation.

Our fixed income and short-term investments (i) represented 92% of our invested assets, (ii) had a weighted average credit rating of "AA-", and (iii) had investment grade holdings representing 96% of the total fixed income and short-term investments portfolio as of June 30, 2024 and December 31, 2023.

For further details on the composition, credit quality, and various risks to which our portfolio is subject, see Item 7A. “Quantitative and Qualitative Disclosures About Market Risk.” of our 2023 Annual Report.

Invested assets increased $328.1 million at June 30, 2024, compared to December 31, 2023, reflecting our active investment of operating and investing cash flows. Operating cash flows during Six Months 2024 were 16% of NPW.

Net Investment Income

The components of net investment income earned were as follows:

After-tax net investment income earned increased 11% in Second Quarter 2024 and 14% in Six Months 2024 compared to the same prior-year periods, primarily driven by higher interest rates, active portfolio management, and operating and investing cash flow deployment.

Realized and Unrealized Gains and Losses

When evaluating securities for sale, our general philosophy is to reduce our exposure to securities and sectors based on economic evaluations of whether (i) the fundamentals for that security or sector have deteriorated or (ii) the timing is appropriate to opportunistically trade for other securities with better economic-return characteristics. Net realized and unrealized gains and losses for the indicated periods were as follows: