Motley Fool Next Index ETF

A series of The RBB Fund, Inc.

Class/Ticker: (TMFX)

SUMMARY PROSPECTUS

December 30, 2021

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus, Statement of Additional Information (“SAI”), reports to shareholders and other information about the Fund at https://www.mfamfunds.com/resources.html. You can also get this information at no cost by calling 1-888-863-8803 or by sending an e-mail request to prospectus@foolfunds.com. The Fund’s Prospectus, dated December 29, 2021, and the Fund’s SAI, dated December 29, 2021, are incorporated by reference into this Summary Prospectus.

Investment Objective

The Motley Fool Next Index ETF (the “Next Fund”) seeks investment results that correspond (before fees and expenses) generally to the total return performance of the Motley Fool Next Index (the “Next Index” – for more on this, see the “Principal Investment Strategies” section).

Fees and Expenses

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Next Fund (“Shares”). This table and the Example below do not include the brokerage commissions that investors may pay on their purchases and sales of Fund Shares.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment):
Management Fees	0.50%
Distribution (12b-1) Fees	0.00%
Other Expenses	0.00%
Total Annual Fund Operating Expenses	0.50%

Example

This Example is intended to help you compare the cost of investing in the Next Fund with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Next Fund for the time periods indicated and then redeem all of your Shares at the end of those periods. The Example also assumes that: (1) your investment has a 5% return each year, and (2) the Next Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 Year	3 Years
$51	$160

Portfolio Turnover

The Next Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Next Fund Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Next Fund’s performance. No portfolio turnover rate is provided for the Next Fund because the Next Fund had not commenced operations prior to the date of this Prospectus.

Principal Investment Strategies

The Next Fund is an exchange-traded fund (“ETF”) and employs a “passive management” – or indexing – investment approach designed to track the total return performance, before fees and expenses, of the Next Index. Motley Fool Asset Management, LLC (the “Adviser”) serves as the investment adviser to the Next Fund. The Next Index was developed by The Motley Fool, LLC (“TMF”), an affiliate of the Adviser.

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The Next Index

The Next Index was established by TMF in 2021 and is a proprietary, rules-based index designed to track the performance of mid- and small-capitalization U.S. companies that have been recommended by TMF’s analysts and newsletters. TMF’s “recommendation universe” includes all companies domiciled in the United States that are either active recommendations of a newsletter published by TMF or are among the 150 highest rated U.S. companies in TMF’s analyst opinion database, subject to universe continuity rules.

To be eligible for inclusion in the Next Index, a security must first meet the existing eligibility criteria of the Motley Fool 100 Index, a proprietary, rules-based index designed to track the performance of the 100 largest, most liquid U.S. companies that have been recommended by TMF’s analysts and newsletters. However, the Next Index excludes the 100 largest securities that meet the Motley Fool 100 Index eligibility criteria, subject to universe continuity rules, and consists of the next largest companies with a 3-month average daily value traded greater than or equal to $1 million. The selection universe consists of companies of all market capitalizations. For this purpose, the Adviser defines small- and mid-capitalization companies as companies having capitalizations similar to, or less than, the companies in the Russell Midcap Index. To create the Motley Fool 100 Index, the largest 100 companies (based on market capitalization, but not restricted to any capitalization constraints) are selected. Given that the selection universe is dynamic, there is no guarantee that the smallest companies that make up the top 100 will always fit the definition of large capitalization, or that the first company (or companies) outside the top 100 will not fit the definition of large capitalization. Historically, the market capitalization weighting methodology has resulted in the Motley Fool 100 Index, under commonly accepted definitions, having attributes of a large capitalization index, and the Next Index having attributes of a small- and mid-capitalization index.

With respect to universe continuity, the Next Index is constructed utilizing a buffering methodology. The buffer is intended to reduce index turnover from movements in constituent weightings that could result in a company dropping out of the index only to be added back with the next rebalance. Specifically, stocks ranked in the top 105 positions based on TMF’s analyst opinion database (70% of the 150-stock target) are automatically included in the candidate universe. Additionally, companies that were previously eligible based on their TMF analyst ratings will still be included as long as their rank is equal to or better than 195 (130% of the 150-stock target). Stocks are then added based on conviction score rank until the 150-stock target is reached.

Once the eligible universe is determined, inclusion in the Motley Fool 100 Index and the Next Index are determined jointly based on market capitalization and index continuity rules. A buffer of 30% of the Motley Fool 100 Index membership target - or 30 stocks - is used to prevent frequent turnover around the Motley Fool 100 Index/Next Index cutoff.

Specifically, stocks ranked in the top 70 positions based on firm-level market capitalization (70% of the 100-stock target) are automatically included in the candidate universe for the Motley Fool 100 Index. Additionally, companies that were previously included in the Motley Fool 100 Index will still be included as long as their market capitalization rank is equal to or better than 130 (130% of the 100-stock target). Stocks are then added to the Motley Fool 100 Index based on conviction score rank until the 100-stock target is reached. The remaining stocks are included in the Next Index.

Each selected company’s share of the Next Index (or “weighting”) is set to equal the company’s share of all Next Index companies’ aggregate market value. The Next Index is reconstituted and rebalanced quarterly. The Next Index will typically include 150 – 450 companies at any one time.

The Next Index is calculated and administered by Solactive AG (the “Index Calculation Agent”), which is not affiliated with the Next Fund, the Adviser or TMF. Additional information regarding the Next Index, including its value, is available on the websites of the Next Index at www.foolindices.com and the Index Calculation Agent, at www.solactive.com.

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The Next Fund’s Investment Strategy

Under normal circumstances, at least 80% of the Next Fund’s total assets (exclusive of any collateral held from securities lending) will be invested in the component securities of the Next Index. The Adviser expects that, over time, if it has sufficient assets, the correlation between the Next Fund’s performance and that of the Next Index, before fees and expenses, will be 95% or better.

The Next Fund will generally use a “replication” strategy to achieve its investment objective, meaning it generally will invest in all of the component securities of the Next Index. However, the Next Fund may use a “representative sampling” strategy, meaning it may invest in a sample of the securities in the Next Index whose risk, return and other characteristics closely resemble the risk, return and other characteristics of the Next Index as a whole, when the Adviser believes it is in the best interests of the Next Fund (e.g., when replicating the Next Index involves practical difficulties or substantial costs, a Next Index constituent becomes temporarily illiquid, unavailable or less liquid, or as a result of legal restrictions or limitations that apply to the Next Fund but not to the Next Index).

The Next Fund generally may invest up to 20% of its total assets (exclusive of any collateral held from securities lending) in securities or other investments not included in the Next Index, but which the Adviser believes will help the Next Fund track the Next Index. For example, the Next Fund may invest in securities that are not components of the Next Index to reflect various corporate actions and other changes to the Next Index (such as reconstitutions, additions and deletions).

The Next Fund is non-diversified for the purposes of the Investment Company Act of 1940, as amended (“1940 Act”), which means that the Next Fund may invest in fewer securities at any one time than a diversified fund. To the extent the Next Index concentrates (i.e., holds more than 25% of its total assets) in the securities of a particular industry, the Next Fund will concentrate its investments to approximately the same extent as the Next Index.

The Next Fund may also seek to increase its income by lending securities.

The Next Fund has elected to be, and intends to qualify each year for treatment as a regulated investment company (“RIC”) under Subchapter M of Subtitle A, Chapter 1, of the Internal Revenue Code of 1986, as amended (the “Code”).

Principal Investment Risks

The value of the Next Fund’s investments may decrease, which will cause the value of the Next Fund’s Shares to decrease. As a result, you may lose money on your investment in the Next Fund, and there can be no assurance that the Next Fund will achieve its investment objective. The Next Fund’s principal risks are presented in alphabetical order to facilitate finding particular risks and comparing them with other funds. Each risk summarized below is considered a “principal risk” of investing in the Next Fund, regardless of the order in which it appears.  Different risks may be more significant at different times depending on market conditions or other factors.

●    Cyber Security Risk. Cyber security risk is the risk of an unauthorized breach and access to the Next Fund’s assets, Fund or customer data (including private shareholder information), or proprietary information, or the risk of an incident occurring that causes the Next Fund, the Adviser, custodian, transfer agent, distributor and other service providers and financial intermediaries to suffer data breaches, data corruption or lose operational functionality or prevent the Next Fund’s investors from purchasing, redeeming or exchanging shares or receiving distributions. The Next Fund and the Adviser have limited ability to prevent or mitigate cyber security incidents affecting third-party service providers, and such third-party service providers may have limited indemnification obligations to the Next Fund or the Adviser. Successful cyber-attacks or other cyber-failures or events affecting the Next Fund or its service providers may adversely impact and cause financial losses to the Next Fund or its shareholders. Issuers of securities in which the Next Fund invests are also subject to cyber security risks, and the value of these securities could decline if the issuers experience cyber-attacks or other cyber-failures.  

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● ETF Risk. The Next Fund is an ETF, and, as a result of an ETF’s structure, it is exposed to the following risks: “Authorized Participants, Market Makers and Liquidity Providers Concentration Risk,” “Secondary Market Trading Risk,” and “Shares May Trade at Prices Other Than NAV Risk.”

●  Authorized Participants, Market Makers and Liquidity Providers Concentration Risk. The Next Fund has a limited number of financial institutions that are institutional investors and may act as authorized participants (“APs”). In addition, there may be a limited number of market makers and/or liquidity providers in the marketplace. To the extent either of the following events occur, Next Fund Shares may trade at a material discount to net asset value (“NAV”) and possibly face delisting: (i) APs exit the business or otherwise become unable to process creation and/or redemption orders and no other APs step forward to perform these services, or (ii) market makers and/or liquidity providers exit the business or significantly reduce their business activities and no other entities step forward to perform their functions. These events, among others, may lead to the Next Fund Shares trading at a premium or discount to NAV. Thus, you may pay more (or less) than the NAV when you buy Shares of the Next Fund in the secondary market, and you may receive less (or more) than NAV when you sell those Shares in the secondary market. A diminished market for an ETF’s shares substantially increases the risk that a shareholder may pay considerably more or receive significantly less than the underlying value of the ETF shares bought or sold.

● Secondary Market Trading Risk. Although Shares are listed on a national securities exchange, the NYSE Arca, Inc. (the “Exchange”), and may be traded on U.S. exchanges other than the Exchange, there can be no assurance that an active or liquid trading market for them will develop or be maintained. In addition, trading in Shares on the Exchange may be halted. During periods of market stress, there may be times when the market price of Shares is more than the NAV intra-day (premium) or less than the NAV intra-day (discount). This risk is heightened in times of market volatility or periods of steep market declines.

● Shares May Trade at Prices Other Than NAV Risk. As with all ETFs, Shares may be bought and sold in the secondary market at market prices. Although it is expected that the market price of Shares will approximate the Next Fund’s NAV, there may be times when the market price of Shares is more than the NAV intra-day (premium) or less than the NAV intra-day (discount). This risk is heightened in times of market volatility or periods of steep market declines.

● Equity Markets Risk. The equity securities held in the Next Fund’s portfolio may experience sudden, unpredictable drops in value or long periods of decline in value. This may occur because of factors that affect securities markets generally or factors affecting specific issuers, industries, or sectors in which the Next Fund invests. Common stocks are generally exposed to greater risk than other types of securities, such as preferred stocks and debt obligations, because common stockholders generally have inferior rights to receive payment from issuers.

● Index Rankings and Methodology Risk.  Factors used by TMF’s analysts in their qualitative and quantitative analysis of companies included in the Next Index, and the weight placed on those factors, may not be predictive of a security’s value and, thus, have an adverse effect on the Next Fund. In addition, changes in TMF’s recommendations or rankings methodologies may have an adverse effect on the Next Fund. Factors that affect a security’s value can change over time, and these changes may not be reflected in the Next Index methodology. Moreover, the methodology and the calculation of the Next Index could be subject to errors. If the composition of the Next Index reflects such errors, the Next Fund’s portfolio can be expected to reflect the errors, too. 

● Market Risk. The trading prices of equity securities and other instruments fluctuate in response to a variety of factors including economic, political, financial, public health crises (such as epidemics or pandemics) or other disruptive events (whether real, expected or perceived) in the U.S. and global markets. The Next Fund’s NAV and market price may fluctuate significantly in response to these and other factors. As a result, an investor could lose money over short or long periods of time.  

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●    Mid-Capitalization Companies Risk. Investments in securities of mid-capitalization companies may involve greater risks than do investments in larger, more established companies. The prices of securities of mid-cap companies tend to be more vulnerable to adverse developments specific to a company or its industry, or the securities markets generally, than are securities of larger capitalization companies.

● New Fund Risk. The Next Fund is a recently organized, non-diversified management investment company with no operating history. In addition, there can be no assurance that the Next Fund will grow to, or maintain, an economically viable size, in which case the Board of Directors (the “Board”) of The RBB Fund, Inc. (the “Company”) may determine to liquidate the Next Fund.

● Non-Diversification Risk. The Next Fund is non-diversified, which means that it may invest a high percentage of its assets in a limited number of securities. Since the Next Fund is non-diversified, its NAV, market price and total returns may fluctuate or fall more than a diversified fund. Gains or losses on a single stock may have a greater impact on the Next Fund.

● Passive Investment Risk. The Next Fund is not actively managed and the Adviser does not attempt to take defensive positions in any market conditions, including adverse markets. The Next Fund and its Adviser will not sell shares of an equity security due to current or projected underperformance of a security, industry, or sector, unless that security is removed from the Next Index or the selling of shares of that security is otherwise required upon a reconstitution of the Next Index as addressed in the Index methodology.

● Portfolio Turnover Risk. In seeking to replicate the Next Index, which is adjusted and rebalanced quarterly, the Next Fund may incur relatively high portfolio turnover. High portfolio turnover may result in increased transaction costs and may lower Fund performance.

● Sector Risk. To the extent the Next Fund invests more heavily in particular sectors of the economy, its performance will be especially sensitive to developments that significantly affect those sectors.

● Consumer Discretionary Sector Risk. The success of consumer product manufacturers and retailers is tied closely to the performance of the overall domestic and global economy, interest rates, competition, and consumer confidence. Success depends heavily on disposable household income and consumer spending. Also, companies in the consumer discretionary sector may be subject to severe competition, which may have an adverse impact on their respective profitability. Changes in demographics and consumer tastes can also affect the demand for, and success of, consumer products and services in the marketplace.

● Health Care Sector Risk. Companies in the health care sector are subject to extensive government regulation and their profitability can be significantly affected by regulatory changes. Other risk factors include rising costs of medical products and services, pricing pressure and limited product lines, loss or impairment of intellectual property rights and litigation regarding product or service liability.

● Industrials Sector Risk. Companies in the industrials sector could be affected by, among other things, government regulation, world events and economic conditions, insurance costs, and labor relations issues.

● Information Technology Sector Risk. In addition to market or economic factors, companies in the information technology sector and companies that rely heavily on technology are particularly vulnerable to rapid changes in technology product cycles, rapid product obsolescence, government regulation and competition.

● Securities Lending Risk. The Next Fund may lend portfolio securities to institutions, such as certain broker- dealers. The Next Fund may experience a loss or delay in the recovery of its securities if the borrowing institution breaches its agreement with the Fund.  

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● Small-Capitalization Companies Risk. The securities of small-capitalization companies may be more vulnerable to adverse issuer, market, political, or economic developments than securities of larger-capitalization companies. The securities of small-capitalization companies generally trade in lower volumes and are subject to greater and more unpredictable price changes than larger capitalization stocks or the stock market as a whole. Some small capitalization companies have limited product lines, markets, and financial and managerial resources and tend to concentrate on fewer geographical markets relative to larger capitalization companies. There is typically less publicly available information concerning smaller-capitalization companies than for larger, more established companies. Small-capitalization companies also may be particularly sensitive to changes in interest rates, government regulation, borrowing costs and earnings.

● Tracking Error Risk. As with all index funds, the performance of the Next Fund and its Index may differ from each other for a variety of reasons. For example, the Next Fund incurs operating expenses and portfolio transaction costs not incurred by the Next Index. In addition, the Next Fund may not be fully invested in the securities of the Next Index at all times or may hold securities not included in the Next Index.

Performance

Performance information for the Next Fund is not included because the Next Fund had not commenced operations prior to the date of this Prospectus. Performance information will be available once the Next Fund has at least one calendar year of performance. The Next Fund’s past performance, before and after taxes, is not necessarily an indication of how the Next Fund will perform in the future and does not guarantee future results. Updated performance information will be available on the Next Fund’s website at www.mfamfunds.com/resources.html.

Management

Investment Adviser

Motley Fool Asset Management, LLC serves as the investment adviser.

Portfolio Managers

Team Member	Primary Titles	Start Date with Fund
Bryan C. Hinmon, CFA®	Chief Investment Officer; Senior Portfolio Manager	Since Inception in 2021
Anthony L. Arsta	Portfolio Manager	Since Inception in 2021

Purchase and Sale of Fund Shares

Shares are listed on a national securities exchange, the Exchange, and investors can only buy and sell Shares through brokers or dealers at market prices, rather than NAV. Because Shares trade at market prices rather than NAV, Shares may trade at a price greater than NAV (premium) or less than NAV (discount). An investor may incur costs attributable to the difference between the highest price a buyer is willing to pay to purchase shares (bid) and the lowest price a seller is willing to accept for shares (ask) when buying or selling shares in the secondary market (the "bid-ask spread"). The median bid-ask spread for the Next Fund’s most recent fiscal year cannot be provided because the Next Fund did not have a sufficient trading history to report trading information and related costs. Once available, information on the Next Fund’s NAV, market price, premiums and discounts, and bid-ask spreads will be provided at www.mfamfunds.com.

The Next Fund issues and redeems Shares at NAV only in large blocks known as “Creation Units,” which only APs (typically, broker-dealers) may purchase or redeem. Creation Units generally consist of 25,000 Shares, though this may change from time to time. The Next Fund generally issues and redeems Creation Units in exchange for a portfolio of securities closely approximating the holdings of the Next Fund (the “Deposit Securities”) and/or a designated amount of U.S. cash.

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Tax Information

Fund distributions are generally taxable as ordinary income, qualified dividend income, or capital gains (or a combination), unless your investment is made through an individual retirement account (“IRA”) or other tax-advantaged account. Distributions on investments made through tax-deferred arrangements may be taxed later upon withdrawal of assets from those accounts.

Financial Intermediary Compensation

If you purchase Shares through a broker-dealer or other financial intermediary (such as a bank) (an “Intermediary”), the Next Fund’s investment adviser, or its affiliates may pay Intermediaries for certain activities related to the Next Fund, including participation in activities that are designed to make Intermediaries more knowledgeable about exchange traded products, including the Next Fund, or for other activities, such as marketing, educational training or other initiatives related to the sale or promotion of Shares. These payments may create a conflict of interest by influencing the Intermediary and your salesperson to recommend the Next Fund over another investment. Any such arrangements do not result in increased Next Fund expenses. Ask your salesperson or visit the Intermediary’s website for more information.

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