Total assets were $4.65 billion as of March 31, 2024, representing an increase of $116.6 million, or 2.6%, from December 31, 2023. NB Bancorp, Inc. Reports First Quarter 2024 Financial Results Investor Contact JP Lapointe, EVP and CFO IR@NeedhamBank.com 781-474-5408 Needham, MA, April 24, 2024 – NB Bancorp, Inc. (the "Company") (Nasdaq Capital Market: NBBK), the holding company of Needham Bank, today announced its first quarter 2024 financial results. SELECTED FINANCIAL HIGHLIGHTS FOR THE FIRST QUARTER OF 2 ...

Economic Conditions and Risks - Changes in interest rates may negatively impact the ability to originate real estate loans and the value of assets, ultimately affecting earnings[291]. - Inflation has risen, leading to increased costs of goods and services, which may negatively impact customers' ability to repay loans[294]. - A significant decline in economic conditions could lead to increased non-performing loans and adversely affect financial performance[295]. - A U.S. government debt default could lead to a decrease in the value of U.S. Treasury securities held by the company, negatively impacting capital position[297]. - The company has a high concentration of loans secured by real estate, increasing the risk of defaults in adverse economic conditions[298]. - Adverse developments in the financial services industry could lead to market-wide liquidity problems, affecting the company's financial condition[299]. - The company faces risks related to funding sources, which may prove insufficient to replace deposits at maturity and support future growth[311]. - Changes in laws and regulations may adversely affect operations and increase costs of operations[312]. Financial Performance - Total assets increased to $4,533,412 thousand as of December 31, 2023, up from $3,592,335 thousand in 2022, representing a growth of 26.2%[474]. - Net loans rose to $3,857,057 thousand, a significant increase of 28.9% from $2,990,417 thousand in the previous year[474]. - Total deposits grew to $3,387,348 thousand, reflecting a 17.3% increase from $2,886,743 thousand in 2022[474]. - Net interest income after provision for credit losses was $116,172 thousand, up from $98,264 thousand, marking an increase of 18.3%[476]. - Noninterest income totaled $15,577 thousand, a 67.5% increase compared to $9,275 thousand in 2022[476]. - Total noninterest expense increased to $119,905 thousand, up 68.5% from $71,151 thousand in the previous year[476]. - Net income for 2023 was $9,825 thousand, a decrease of 67.3% from $30,065 thousand in 2022[476]. - Comprehensive income for the year was $12,329 thousand, down from $17,936 thousand in 2022[479]. Capital and Funding - Minimum capital requirements include a common equity Tier 1 capital ratio of 4.5% and a total capital ratio of 8%[321]. - The company may need to raise additional capital to support growth, which could dilute existing shareholders' interests[331]. - The company issued 40,997,500 common shares, raising $400,375 thousand net of costs[481]. - The company incurred approximately $9.6 million in conversion costs related to its transition to a publicly traded stock organization[490]. Compliance and Regulatory Risks - Compliance with anti-money laundering laws and reporting obligations to FinCEN is critical, with potential fines for non-compliance[317]. - The company faces significant legal risks from regulatory investigations and private actions, which could lead to financial liability[328]. - The company operates three new business lines related to cannabis, money services, and ATMs, requiring enhanced compliance procedures[313]. - The Federal Reserve Board's monetary policies could adversely affect the company's financial condition and results of operations[319]. Operational Risks - The company faces significant operational risks due to reliance on technology, including potential failures, interruptions, and security breaches that could adversely affect financial condition and operations[338]. - Outsourcing critical operations to third-party service providers exposes the company to risks if these vendors fail to perform as per contractual agreements, which could materially impact business operations[340]. - The introduction of new products and services may incur significant costs and expose the company to operational risks[334]. Credit Losses and Allowance - The allowance for credit losses increased to $32,222 thousand from $25,028 thousand, indicating a rise in provisions for potential loan losses[474]. - Provision for credit losses increased significantly to $13,885 thousand in 2023 from $6,700 thousand in 2022, indicating a rise in expected credit losses[484]. - The allowance for credit losses (ACL) was adjusted by approximately $1.2 million for loans and $1.8 million for unfunded commitments upon the adoption of ASC 326[518]. - The Company’s ACL is based on an evaluation of the loan portfolio, current economic conditions, and historical loan loss experience, utilizing a third-party CECL model for estimation[513]. - The reserve for unfunded commitments was increased by $1.8 million, which reduced equity by $1.3 million after tax effects[526]. - The allowance for credit losses for unfunded loan commitments increased to $6.0 million as of December 31, 2023, from zero as of December 31, 2022[591]. Revenue and Income Sources - The Company reported total revenues from contracts with customers of $7,817,000 for the year ended December 31, 2023, compared to $5,138,000 in 2022, representing a year-over-year increase of approximately 52%[540]. - ATM and interchange income increased to $1,224,000 in 2023 from $1,071,000 in 2022, reflecting a growth of about 14.3%[540]. - Other customer service fees surged to $6,066,000 in 2023, compared to $3,629,000 in 2022, indicating a significant increase of around 67.2%[540]. Investments and Securities - As of December 31, 2023, the total amortized cost of available-for-sale (AFS) securities was $204.3 million, with a fair value of $189.5 million, reflecting an unrealized loss of $14.8 million[556]. - The net unrealized losses on AFS securities decreased from $18.5 million as of December 31, 2022, to $14.8 million as of December 31, 2023[558]. - The Company held $49.6 million in investment securities pledged to secure borrowings with the Federal Reserve Bank as of December 31, 2023, compared to none in 2022[556]. - The Company did not sell any AFS securities during the years ended December 31, 2023, and 2022[557].

Exhibit 99.1 NB Bancorp, Inc. Reports Full Year 2023 Financial Results Investor Contact ● Net income was $9.8 million for 2023, which was negatively impacted by the previously mentioned one-time expenses, most significantly the $19.1 million expense for the cash and stock contribution to the Needham Bank Charitable Foundation. ● Net income, excluding conversion and IPO-related expenses, was $34.3 million for the year ended December 31, 2023. ● Book value and tangible book value per share were $17.75 and $17 ...

Part I. Financial Information [Financial Statements](index=5&type=section&id=Item%201%2E%20Financial%20Statements) The unaudited statements show significant growth in assets, loans, and deposits, reflecting the adoption of CECL and ongoing expansion Consolidated Balance Sheet Highlights (in thousands) | Metric | September 30, 2023 | December 31, 2022 | | :--- | :--- | :--- | | Total Assets | $4,231,792 | $3,592,335 | | Loans Receivable, net | $3,683,262 | $2,990,417 | | Total Deposits | $3,436,659 | $2,886,743 | | FHLB Borrowings | $345,634 | $293,082 | | Total Equity | $365,701 | $344,065 | Consolidated Income Statement Highlights (in thousands) | Metric | Nine Months Ended Sep 30, 2023 | Nine Months Ended Sep 30, 2022 | | :--- | :--- | :--- | | Net Interest Income | $95,200 | $73,888 | | Provision for Credit Losses | $7,984 | $4,100 | | Non-Interest Income | $12,322 | $6,903 | | Net Income | $23,444 | $18,037 | - The financial statements belong to NB Financial, MHC, as the conversion to NB Bancorp, Inc was not yet complete[6](index=6&type=chunk) - The company adopted the **CECL standard (ASC 326)** on January 1, 2023, which **decreased retained earnings by $2.1 million**[17](index=17&type=chunk)[32](index=32&type=chunk) - Loans to the cannabis industry **increased significantly to $158.5 million** from $58.3 million at year-end 2022[64](index=64&type=chunk) - The company is converting from a mutual to a stock holding company, incurring **$1.8 million in deferred costs**[170](index=170&type=chunk)[171](index=171&type=chunk) - The Bank was considered **well-capitalized** with a Community Bank Leverage Ratio of **9.13%**, exceeding the minimum requirement[111](index=111&type=chunk) [Management's Discussion and Analysis (MD&A)](index=64&type=section&id=Item%202%2E%20Management's%20Discussion%20and%20Analysis%20of%20Financial%20Condition%20and%20Results%20of%20Operations) Management discusses strong loan and deposit growth, rising net interest income, and strategies for managing risk - Net loans grew by **$692.8 million**, driven by commercial real estate (+$273.4M) and commercial and industrial (+$224.3M) loans[189](index=189&type=chunk) - Deposits grew by **$549.9 million**, with core deposits increasing by **$476.3 million**, partly due to industry turmoil and branch expansion[191](index=191&type=chunk)[192](index=192&type=chunk)[193](index=193&type=chunk) - Noninterest income was boosted by a one-time **$3.5 million employee retention credit** and a **$1.9 million increase** in customer service fees[222](index=222&type=chunk)[223](index=223&type=chunk) - The provision for credit losses increased by **$3.9 million**, primarily due to significant loan portfolio growth[221](index=221&type=chunk) - The company maintains substantial liquidity from deposits and has access to **$465.8 million** from the FHLB and **$45.3 million** from the Federal Reserve[245](index=245&type=chunk) - The Bank **exceeded all regulatory capital requirements** and was categorized as well-capitalized as of September 30, 2023[251](index=251&type=chunk) Year-to-Date Performance vs. Prior Year (Nine Months Ended Sep 30) | Metric (in millions) | 2023 | 2022 | Change | % Change | | :--- | :--- | :--- | :--- | :--- | | Net Interest Income | $95.2 | $73.9 | +$21.3 | +28.8% | | Provision for Credit Losses | $8.0 | $4.1 | +$3.9 | +94.7% | | Noninterest Income | $12.3 | $6.9 | +$5.4 | +78.5% | | Noninterest Expense | $67.5 | $52.4 | +$15.2 | +29.0% | | Net Income | $23.4 | $18.0 | +$5.4 | +30.0% | Interest Rate Sensitivity Analysis (as of Sep 30, 2023) | Rate Shock (bps) | % Change in Net Interest Income | % Change in Economic Value of Equity | | :--- | :--- | :--- | | +300 | -3.5% | -2.8% | | +200 | -2.4% | -1.3% | | +100 | -0.9% | -0.2% | | -100 | 0.0% | -1.5% | | -200 | -0.7% | -5.0% | [Controls and Procedures](index=87&type=section&id=Item%204%2E%20Controls%20and%20Procedures) Management concluded that the company's disclosure controls and internal financial reporting controls were effective - Management concluded that the company's disclosure controls and procedures were **effective** as of the end of the reporting period[255](index=255&type=chunk) - **No material changes** in internal control over financial reporting occurred during the quarter[256](index=256&type=chunk) Part II. Other Information [Legal Proceedings and Other Disclosures](index=89&type=section&id=Item%201%2E%20Legal%20Proceedings%20and%20Other%20Disclosures) The company reports no material legal actions and notes its status as an emerging growth company exempts it from certain disclosures - The company is subject to various legal actions from the normal course of business, which are **not expected to have a material effect**[258](index=258&type=chunk) - As an emerging growth company, disclosures for **Risk Factors** and **Market Risk** are not required[254](index=254&type=chunk)[259](index=259&type=chunk)