Harbor Small Cap Earners ETF Summary Prospectus

Harbor Small Cap Earners ETF (formerly, Harbor AlphaEdge™ Small Cap Earners ETF)

EBIT

Summary Prospectus – March 1, 2026 (as amended August 31, 2026)

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 and other information about the Fund online at harborcapital.com/prospectus. You can also get this information at no cost by calling 800-422-1050 or by sending an email request to funddocuments@harborcapital.com. If you purchase shares of the Fund through a financial intermediary, the prospectus and other information will also be available from your financial intermediary. The current prospectus and statement of additional information, dated March 1, 2026, as amended or supplemented from time to time, are incorporated by referenced into this summary prospectus and may be obtained, free of charge, at the website, phone number or email address noted above.

Investment Objective

The Fund seeks to provide investment results that correspond, before fees and expenses, to the performance of the Harbor Small Cap Earners Index (formerly, Harbor AlphaEdge™ Small Cap Earners Index) (the “Index”).

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the table and example below.

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

	Rate
Management Fees	0.29%
Distribution and Service (12b-1) Fees	None
Other Expenses1	0.00%
Total Annual Fund Operating Expenses	0.29%

1 Pursuant to the Investment Advisory Agreement, the Advisor pays all of the operating expenses of the Fund, except for (i) the fee payment under the Investment Advisory Agreement; (ii) payments under the Fund’s 12b-1 plan (if any); (iii) the costs of borrowing, including interest and dividend expenses; (iv) taxes and governmental fees; (v) acquired fund fees and expenses; (vi) brokers’ commissions and any other transaction-related expenses and fees arising out of transactions effected on behalf of the Fund; (vii) costs of holding shareholder meetings; and (viii) litigation and indemnification expenses and other extraordinary expenses not incurred in the ordinary course of the Fund’s business.

Expense Example

This Expense Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other exchange-traded funds. The Expense Example assumes that you invest $10,000 in the Fund for the time periods indicated. The Expense Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, under these assumptions, your costs would be:

	One Year	Three Years	Five Years	Ten Years
ETF	$30	$93	$163	$368

Portfolio Turnover

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when shares of the Fund are held in a taxable account. These costs, which are not reflected in the Annual Fund Operating Expenses or in the Expense Example, do affect the

Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 49%. Portfolio turnover rate excludes investments received or delivered from in-kind processing of creation unit purchases or redemptions.

Principal Investment Strategy

The Fund employs an indexing (or “passive”) investment approach designed to track the performance of the Index, which is constructed by Harbor Capital Advisors, Inc. (“Harbor Capital”, the “Advisor” or the “Index Provider”) in accordance with a proprietary, rules-based methodology. The Fund invests at least 80% of its total assets in securities that are included in the Index. The Index is designed to deliver exposure to equity securities of small cap U.S. companies that are profitable, or “small cap earners,” based on the Index Provider’s methodology.

Constituents of the Russell 2000® Index, which intends to track the performance of 2,000 U.S. small-cap equities, including real estate investment trusts (“REITs”), based on free float market capitalization at the time of Index reconstitution are eligible for inclusion in the Index (the “Index Universe”). All companies in the Index Universe that are “profitable” at the time of the Index reconstitution based on the Index Provider’s methodology are included in the Index. The Index Provider uses operating margin to determine profitability. Operating margin is one of several ways to measure a company’s profitability and is calculated by dividing a company’s operating income (or earnings) by its sales (or revenues). The Index Provider considers companies with operating margin of greater than or equal to 1%, measured using two calculations for the prior 12 quarters, to be profitable. Specifically, the Index Provider considers a company to be profitable where it meets both of the following profitability criteria: (1) median trailing 12-month operating margin over the prior 12 quarters greater than or equal to 1%; and (2) aggregate operating margin over the prior 12 quarters greater than or equal to 1%. Each Index constituent is weighted by profitability relative to other Index constituents over the trailing three-year period. As of December 31, 2025, the largest market capitalization in the Index Universe was $31.29 billion and the median market capitalization in the Index Universe was $987 million. The market capitalization range of the Index Universe is expected to change frequently.

The Index has been created by Harbor Capital and is calculated, published and distributed by Solactive AG (“Solactive”). The Index is reconstituted and rebalanced twice annually in accordance with the methodology. The Fund will concentrate its investments in a particular industry or group of industries from time to time to approximately the same extent that the Index concentrates in an industry or group of industries. The Index and, therefore, the Fund may also from time to time have significant exposure to particular sectors. As of December 31, 2025, the Index has significant exposure to the financials sector. The constituents of the Index, including the number of constituents and the degree to which these constituents represent certain sectors, industries, or groups of industries may change over time.

The Index Provider determines whether an issuer is a U.S. issuer by reference to the Russell 2000® Index methodology. For purposes

Summary Prospectus

Harbor Small Cap Earners ETF (formerly, Harbor AlphaEdge™ Small Cap Earners ETF)

of that methodology, an issuer is deemed to be a U.S. issuer if it is incorporated in, has a stated headquarters in, and trades in the U.S.; if any of these do not match, the methodology provides for consideration of certain additional factors.

The Advisor uses a representative sampling indexing approach to attempt to approximate, before fees and expenses, the investment performance of the Index. The Fund will invest in a representative sample of securities with an investment profile, collectively, similar to that of the Index. The securities selected are expected to have, in the aggregate, investment characteristics, fundamental characteristics and liquidity measures similar to those of the Index. The Fund may or may not hold all of the securities in the Index. The Fund may also seek exposure to the Index through investments in Harbor Small Cap Earners ETF, which also tracks the Index. The Fund does not take temporary defensive positions when markets decline or appear overvalued.

Principal Risks

There is no guarantee that the investment objective of the Fund will be achieved. Stocks fluctuate in price and the value of your investment in the Fund may go down. This means that you could lose money on your investment in the Fund or the Fund may not perform as well as other investment options. Principal risks impacting the Fund (in alphabetical order after the first six risks) include:

Market Risk: Securities markets are volatile and can decline significantly in response to adverse market, economic, political, regulatory or other developments, which may lower the value of securities held by the Fund, sometimes rapidly or unpredictably. Events such as war, military conflict, geopolitical disputes, acts of terrorism, social or political unrest, natural disasters, recessions, inflation, rapid interest rate changes, supply chain disruptions, tariffs and other restrictions on trade, sanctions, the spread of infectious illness or other public health threats, or the threat or potential of one or more such events and developments, could also significantly impact the Fund and its investments.

Equity Risk: The values of equity securities may decline due to general market conditions that are not specifically related to a particular company, such as real or perceived adverse economic conditions, changes in the general outlook for corporate earnings, changes in interest or currency rates or adverse investor sentiment generally. They may also decline due to factors that affect a particular industry or industries, such as labor shortages or increased production costs and competitive conditions within an industry. Equity securities generally have greater price volatility than fixed income securities.

Small Cap Risk: The Fund’s performance may be more volatile because it invests in issuers that are smaller companies. Smaller companies may have limited product lines, markets and financial resources. Securities of smaller companies are usually less stable in price and less liquid than those of larger, more established companies. Additionally, small cap stocks may fall out of favor relative to mid or large cap stocks, which may cause the Fund to underperform other equity funds that focus on mid or large cap stocks. In addition, the Index’s focus on “profitable” companies may cause the Fund to underperform the broader Index Universe.

Risks Associated with Index Funds: Because the Fund uses a representative sampling index strategy, the Fund will not fully replicate the Index. The Fund is managed to seek to track, before fees and expenses, the performance of the Index. Therefore, unless a specific security is removed from the Index because it no longer qualifies to be included in the Index, the Fund generally would not sell a security because the security’s issuer is in financial trouble.

If a specific security is removed from the Index, it is possible that the Fund may be forced to sell such security at an inopportune time or for prices other than at current market values, which could have a negative effect on the Fund’s performance. The Advisor will not use techniques or defensive strategies designed to lessen the effects of market volatility or to reduce the impact of periods of market decline. Thus, based on market and economic conditions, the Fund’s performance could be lower than funds that actively shift their portfolio assets to take advantage of market opportunities or to lessen the impact of a market decline or a decline in the value of one or more securities. Unusual market conditions or other unforeseen circumstances (such as natural disasters, pandemics, political unrest or war) may impact the Index Provider and could cause the Index Provider to change the rebalance schedule of the Index. This could cause the Index to vary from its normal or expected composition. Apart from scheduled rebalances, the Index Provider or its agents may carry out additional ad hoc rebalances to the Index due to reaching certain weighting constraints, unusual market conditions or corporate events or, for example, to correct an error in the selection of index constituents. When the Index is rebalanced and the Fund in turn rebalances its portfolio to attempt to increase the correlation between the Fund’s portfolio and the Index, any transaction costs and market exposure arising from such portfolio rebalancing will be borne directly by the Fund and its shareholders. Therefore, errors and additional ad hoc rebalances carried out by the Index Provider to the Index may increase the costs to and the tracking error risk of the Fund.

Additional risks associated with index funds include:

Index Construction Risk: The Index Provider identifies companies for the Index based on a proprietary methodology. The theories and assumptions upon which the Index Provider bases the Index and/or the methodology used in evaluating companies for the Index may be unsound. The Index Provider and Solactive rely on third-party data they believe to be reliable in constructing the Index, but the providers of such data do not guarantee its accuracy, availability or timeliness. The Fund may outperform or underperform other funds that invest in similar asset classes but employ different investment styles. Errors in the construction or calculation of the Index may occur from time to time and any such errors may not be immediately identified and corrected, which may have an adverse impact on the Fund and its shareholders. There is no guarantee that the construction methodology will accurately provide the intended exposure.

Index Tracking Risk: The Fund is not expected to track the performance of the Index at all times with perfect accuracy. The Fund’s return may not track the performance of the Index for a number of reasons. For example, tracking error may occur because of differences between the securities held in the Fund’s portfolio and the Index constituents, transaction costs incurred by the Fund, the Fund’s holding of uninvested cash, or differences in timing of the accrual of or the valuation of dividends or interest. Any transaction costs and market exposure arising from rebalancing the Fund’s portfolio to reflect changes in the composition of the Index will be borne directly by the Fund and its shareholders. The Fund may not be able to invest in certain Index constituents or may not be able to invest in them in the exact proportions in which they are represented in the Index, due to legal restrictions, potential adverse tax consequences or other regulatory reasons. The risk that the Fund may not track the performance of the Index may be magnified during times of heightened market volatility or other unusual market conditions. For tax efficiency purposes, the Fund may sell certain securities to realize losses causing it to deviate from the Index.

Summary Prospectus

Harbor Small Cap Earners ETF (formerly, Harbor AlphaEdge™ Small Cap Earners ETF)

Concentration Risk: To the extent that a significant portion of the Index consists of a particular industry or group of industries, the Fund may have significant exposure to such industry or group of industries and will be subject to the risk that economic, political or other conditions that have a negative effect on that industry or group of industries will negatively impact the Fund to a greater extent than if the Fund’s assets were invested in a wider variety of industry or group of industries. Companies in the financials sector are subject to extensive government regulation and can be significantly affected by changes in interest rates, availability and cost of capital funds, the rate of corporate and consumer debt defaults, and price competition.

Risks Associated with Exchange-Traded Funds: As an ETF, the Fund is subject to the following risks:

Authorized Participant Concentration/Trading Risk: Only authorized participants (“APs”) may engage in creation or redemption transactions directly with the Fund. The Fund has a limited number of institutions that may act as APs and such APs have no obligation to submit creation or redemption orders. Consequently, there is no assurance that APs will establish or maintain an active trading market for the shares. This risk may be heightened to the extent that securities held by the Fund are traded outside a collateralized settlement system. In that case, APs may be required to post collateral on certain trades on an agency basis (i.e., on behalf of other market participants), which only a limited number of APs may be able to do. In addition, to the extent that APs exit the business or are unable to proceed with creation and/or redemption orders with respect to the Fund and no other AP is able to step forward to create or redeem Creation Units (as defined below), this may result in a significantly diminished trading market for shares, and shares may be more likely to trade at a premium or discount to the Fund’s net asset value and to face trading halts and/or delisting. This risk may be heightened during periods of volatility or market disruptions.

Cash Transactions Risk: The Fund may effect some or all of its creations and redemptions for cash rather than in-kind. As a result, an investment in the Fund may be less tax-efficient than an investment in an ETF that effects all of its creations and redemptions in-kind. Because the Fund may effect redemptions for cash, it may be required to sell portfolio securities in order to obtain the cash needed to distribute redemption proceeds. A sale of portfolio securities may result in capital gains or losses and may also result in higher brokerage costs. To the extent costs are not offset by transaction fees charged by the Fund to APs, the costs of cash transactions will be borne by the Fund.

Premium/Discount Risk: The market price of the Fund’s shares will generally fluctuate in accordance with changes in the Fund’s net asset value as well as the relative supply of and demand for shares on the Exchange. The Advisor cannot predict whether shares will trade below, at or above their net asset value because the shares trade on the Exchange at market prices and not at net asset value. Price differences may be due, in large part, to the fact that supply and demand forces at work in the secondary trading market for shares will be closely related, but not identical, to the same forces influencing the prices of the holdings of the Fund trading individually or in the aggregate at any point in time. This may result in the Fund’s shares trading significantly above (premium) or below (discount) the Fund’s net asset value, which will be reflected in the intraday bid/ask spreads and/or the closing price of shares as compared to net asset value. However, given that shares can only be purchased and redeemed in Creation Units to and from broker-dealers and large institutional investors that have entered into participation agreements (unlike shares of closed-end funds, which frequently trade at appreciable discounts from, and sometimes

at premiums to, their net asset value), the Advisor believes that large discounts or premiums to the net asset value of shares should not be sustained. During stressed market conditions, the market for the Fund’s shares may become less liquid in response to deteriorating liquidity in the market for the Fund’s underlying portfolio holdings, which could in turn lead to differences between the market price of the Fund’s shares and their net asset value.

Issuer Risk: An adverse event affecting a particular issuer in which the Fund is invested, such as an unfavorable earnings report, may depress the value of that issuer’s securities, sometimes rapidly or unpredictably.

Large Shareholder Risk: Certain large shareholders including authorized participants (“AP”), third-party investors, the Advisor, affiliates of the Advisor, market makers, or other entities, including funds or accounts over which the Advisor, an affiliate of the Advisor or a third-party intermediary has investment discretion, such as those investing through one or more model portfolios, may from time to time own or control a substantial amount of the Fund’s shares. There is no requirement that these shareholders maintain their investment in the Fund. There is a risk that such large shareholders or that the Fund’s shareholders generally may redeem all or a substantial portion of their investments in the Fund in a short period of time, including as a result of an asset allocation decision made by the Advisor, an affiliate of the Advisor or a third-party intermediary, which could have a significant negative impact on the Fund’s NAV, liquidity, and brokerage costs. Large redemptions could also result in tax consequences to shareholders and impact the Fund’s ability to implement its investment strategy. In addition, transactions by large shareholders may account for a large percentage of the trading volume on the listing exchange and may, therefore, have a material upward or downward effect on the market price of the shares.

New Fund Risk: There can be no assurance that the Fund will grow to or maintain an economically viable size, in which case the Board of Trustees may determine to liquidate the Fund. The Board of Trustees may liquidate the Fund at any time in accordance with the Declaration of Trust and governing law. As a result, the timing of the Fund’s liquidation may not be favorable.

REIT Risk: REITs in which the Fund invests may decline in value as a result of factors affecting the real estate sector, such as changes in real estate values, changes in property taxes and government regulation affecting zoning, land use and rents, changes in interest rates, changes in the cash flow of underlying real estate assets, levels of occupancy, and market conditions, as well as the management skill and creditworthiness of the issuer. Investments in REITs are also subject to additional risks, including the risk that REITs are unable to generate cash flow to make distributions to unitholders and fail to qualify for favorable tax treatment under the Internal Revenue Code of 1986, as amended.

Summary Prospectus

Harbor Small Cap Earners ETF (formerly, Harbor AlphaEdge™ Small Cap Earners ETF)

Performance

The following bar chart and tables are intended to help you understand the risks and potential rewards of investing in the Fund. The bar chart shows how the performance of the Fund has varied from one calendar year to another over the periods shown. The table shows how the Fund’s average annual total returns compare to the returns of the Fund’s benchmark index, which includes securities with investment characteristics similar to those held by the Fund, and additional indexes over time. Please note that the Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information please visit the Fund’s website at harborcapital.com or call 800-422-1050.

Calendar Year Total Returns

During the time period shown in the bar chart, the Fund’s highest and lowest returns for a calendar quarter were:

	Total Returns	Quarter/Year
Best Quarter	8.53%	Q3 2025
Worst Quarter	-6.99%	Q1 2025

Average Annual Total Returns — As of December 31, 2025

	One Year	Annualized	Inception Date
	One Year	Since Inception	Inception Date
Harbor Small Cap Earners ETF
Before Taxes	6.86%	11.45%	07/09/2024
After Taxes on Distributions	6.34%	10.46%
After Taxes on Distributions and Sale of Fund Shares	4.39%	8.54%
Comparative Indices (reflects no deduction for fees, expenses or taxes)
S&P 500 Index^	17.88%	16.32%
Harbor Small Cap Earners Index^^	7.61%	11.66%
Russell 2000® Index^^	12.81%	16.10%

This index represents a broad measure of market performance.

̂̂

The Advisor considers this index to be representative of the Fund’s principal investment strategies and therefore the appropriate benchmark index for the Fund for performance comparison purposes.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns will depend on a shareholder’s individual tax situation and may differ from those shown. The after-tax returns shown are not relevant to tax-exempt shareholders or shareholders who hold their Fund shares through a tax-deferred arrangement, such as a 401(k) plan or individual retirement account. In some cases, average annual total return “After Taxes on Distributions and Sale of Fund Shares” may exceed the return “Before Taxes” and/or “After Taxes on Distributions” due to an assumed tax benefit for any losses on a sale of Fund shares at the end of the measurement period.

Portfolio Management

Investment Advisor

Harbor Capital Advisors, Inc.

Portfolio Managers

The portfolio managers are jointly and primarily responsible for the day-to-day investment decision making for the Fund.

Stephen Cook, Chief Operating Officer and Senior Vice President, has managed the Fund since 2024.

Elizabeth Despain, Associate Index Portfolio Manager at Harbor Capital, has managed the Fund since March 2025.

James Erceg, Executive Vice President and Head of Product at Harbor Capital, has managed the Fund since 2024.

Buying and Selling Fund Shares

Individual Fund shares may only be bought and sold in the secondary market through a broker or dealer at a market price. Shares of the Fund are listed and traded on an exchange at market price throughout the day rather than at NAV and may trade at a price greater than the Fund’s NAV (premium) or less than the Fund’s 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 Fund shares in the secondary market (the “bid-ask spread”). Recent information, including information regarding the Fund’s NAV, market price, premiums and discounts, and bid-ask spread, is available at harborcapital.com.

Exchange	Ticker

NYSE Arca, Inc.	EBIT