Summary Prospectus by Investment Company - Form 497K

Aquila High Income Fund Summary Prospectus | May 1, 2024

	Tickers:	Class A - ATPAX	Class C - ATPCX	Class F - ATPFX
		Class I - ATIPX	Class Y - ATPYX

This summary prospectus is designed to provide investors with key Fund information in a clear and concise format. Before you invest, you may want to review the Fund's complete Prospectus, which contains more information about the Fund and its risks. You can find the Fund's Prospectus, reports to shareholders, and other information about the Fund online at www.aquilafunds.com/prospectuses-reports/. You can also get this information at no cost by calling 800-437-1000 (toll-free) or by sending an e-mail request to [email protected]. If you purchase shares of the Fund through a broker-dealer or other financial intermediary (such as a bank), the Prospectus and other information will also be available from your financial intermediary. The Fund's Prospectus and Statement of Additional Information, both dated May 1, 2024, are incorporated by reference into this summary prospectus and may be obtained, free of charge, at the website, phone number or e-mail address noted above.

Investment Objectives

The Fund's objective is to obtain high current income. Capital appreciation is a secondary objective when consistent with its primary objective.

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 tables and examples below. If you invest in Class A Shares, you may qualify for sales charge discounts if you and your immediate family invest, or agree to invest in the future, at least $25,000 in the Fund or in other funds in the Aquila Group of Funds. More information about these and other discounts is available from your financial advisor and under "Alternative Purchase Plans" on page 31 of the Fund's Prospectus, "Sales Charges - Class A Shares" on page 33 of the Prospectus, "Broker-Defined Sales Charge Waiver Policies" on page 50 of the Prospectus, and "Purchase, Redemption, and Pricing of Shares" on page 53 of the Statement of Additional Information (the "SAI"). If you invest in Class F Shares or Class Y Shares, you may be required to pay a commission to a broker, which is not reflected in the Expense Example.

	Class A Shares	Class C Shares	Class F Shares	Class I Shares	Class Y Shares
Shareholder Fees (fees paid directly from your investment)
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	4.00%	None	None	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lesser of redemption value or purchase price)	None(1)	1.00%	None	None	None
Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)
Management Fee	0.65%	0.65%	0.65%	0.65%	0.65%
Distribution and Service (12b-1) Fees	0.20%	1.00%	None	0.40%	None
Other Expenses(2)	0.57%	0.56%	0.52%	0.44%	0.57%
Acquired Fund Fees and Expenses	0.01%	0.01%	0.01%	0.01%	0.01%
Total Annual Fund Operating Expenses Plus Acquired Fund Fees and Expenses(2)	1.43%	2.22%	1.18%	1.50%	1.23%
Total Fee Waivers(3)	-0.22%	-0.22%	-0.22%	-0.22%	-0.22%
Total Annual Fund Operating Expenses After Fee Waivers Plus Acquired Fund Fees and Expenses(3)	1.21%	2.00%	0.96%	1.28%	1.01%

(1)	Shareholders who purchase $1 million or more of Class A Shares do not pay an initial sales charge but may pay a contingent deferred sales charge of up to 1% for redemptions within 18 months of purchase.

(2)	Restated to reflect current expenses.

(3)

The Manager has contractually undertaken to waive fees and/or reimburse Fund expenses (other than portfolio transaction and other investment related costs, prime broker fees and expenses, interest expense, dividend expenses related to short sales if any, and acquired fund fees and expenses) so that total Fund expenses will not exceed 1.20% for Class A Shares, 1.99% for Class C Shares, 0.95% for Class F Shares, 1.27% for Class I Shares and 1.00% for Class Y Shares. These expense limitations are in effect until April 30, 2025. Prior to April 30, 2025, the arrangement may not be terminated without the approval of the Board of Trustees. If total annual Fund operating expenses of any class in a fiscal year are less than the respective expense caps described above, as well as below the expense cap which was in place at the time of such reimbursed expenses or waived fees, the Manager may recover the difference between the total annual Fund operating expenses of the class and the respective expense cap, up to, but not more than, the amount, if any, by which reimbursed expenses and waived fees over the preceding rolling three year period have not been paid by the Fund to the Manager.

Example

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same except for year one (which considers the effect of the expense limitation). Six years after the date of purchase, Class C Shares automatically convert to Class A Shares. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Class A Shares	$518	$814	$1,130	$2,026
Class C Shares	$303	$673	$1,170	$2,154
Class F Shares	$ 98	$353	$ 628	$1,412
Class I Shares	$130	$453	$ 798	$1,772
Class Y Shares	$103	$369	$ 655	$1,469

You would pay the following expenses if you did not redeem your Class C Shares:

Class C Shares

$203

$673

$1,170

$2,154

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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 rate may indicate higher transaction costs and may result in higher taxes when 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 Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 34% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests, under normal circumstances, at least 80% of its net assets plus any borrowings for investment purposes in income-producing securities. Such securities may be rated at any level by nationally recognized statistical rating organizations or they may be unrated. It is anticipated that the Fund's portfolio will typically include a high proportion, perhaps even 100%, of high-yield/high-risk securities rated below investment grade. Such securities are sometimes called "junk bonds."

The bonds the Fund purchases can be of any maturity but the average effective weighted maturity of the Fund's portfolio will normally be within one year of the average maturity of the Bloomberg US Corporate High Yield Total Return Index Value Unhedged. The average maturity of the Index as of December 31, 2023 was 4.85 years.

In addition to considering economic factors such as the effect of interest rates on the Fund's investments, Aquila Investment Management LLC (the "Manager") applies a "bottom up" approach in choosing investments. The Manager considers the individual characteristics of each potential investment in an income-producing security to determine if it is an attractive investment opportunity and consistent with the Fund's investment policies. The Manager also employs a relative value analysis and fundamental credit research on potential investments in an effort to identify companies with attractive characteristics such as improving balance sheets, improving cash flow or interest coverage, improving earnings, hidden or unappreciated value, management quality, and/or strong business models.

Within the parameters of the Fund's specific investment policies, the Fund may invest without limit in foreign debt, including debt of emerging markets issuers. The Fund may also invest in subordinated securities and may hold cash or other short-term investments.

Principal Risks

You may lose money by investing in the Fund. Following is a summary description of certain risks of investing in the Fund.

Market Risk. The market prices of securities or other assets held by the Fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political, or regulatory conditions, political instability, recessions, inflation, changes in interest or currency rates, lack of liquidity in the bond markets, the spread of infectious illness or other public health issues, weather or climate events, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors or adverse investor sentiment. When market prices fall, the value of your investment will likely go down. A change in financial condition or other event affecting a single issuer or market may adversely impact securities markets as a whole.

In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); global pandemics; measures to address budget deficits; downgrades of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; and public sentiment. The long-term impact of the COVID-19 pandemic and its subsequent variants on economies, markets, industries and individual issuers, are not known. Some sectors of the economy and individual issuers have experienced or may experience particularly large losses. Periods of extreme volatility in the financial markets, reduced liquidity of many instruments, increased government debt, inflation, and disruptions to supply chains, consumer demand and employee availability, may continue for some time.

Raising the ceiling on U.S. government debt has become increasingly politicized. Any failure to increase the total amount that the U.S. government is authorized to borrow could lead to a default on U.S. government obligations, with unpredictable consequences for economies and markets in the U.S. and elsewhere. Inflation and interest rates have increased and may rise further. These circumstances could adversely affect the value and liquidity of the Fund's investments, impair the Fund's ability to satisfy redemption requests, and negatively impact the Fund's performance. In addition, inflation, rising interest rates, global supply chain disruptions and other market events could adversely affect the companies or issuers in which the Fund invests. Following Russia's invasion of Ukraine, Russian securities lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future political, geopolitical or other events or conditions.

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Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. U.S. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments, could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the Fund invests.

The U.S. and other countries are periodically involved in disputes over trade and other matters, which may result in tariffs, investment restrictions and adverse impacts on affected companies and securities. For example, the U.S. has imposed tariffs and other trade barriers on Chinese exports, has restricted sales of certain categories of goods to China, and has established barriers to investments in China. Trade disputes may adversely affect the economies of the U.S. and its trading partners, as well as companies directly or indirectly affected and financial markets generally. The U.S. government has prohibited U.S. persons, such as the Fund, from investing in Chinese companies designated as related to the Chinese military. These and possible future restrictions could limit the Fund's opportunities for investment and require the sale of securities at a loss or make them illiquid. Moreover, the Chinese government is involved in a longstanding dispute with Taiwan that has included threats of invasion. If the political climate between the U.S. and China does not improve or continues to deteriorate, if China were to attempt unification of Taiwan by force, or if other geopolitical conflicts develop or get worse, economies, markets and individual securities may be severely affected both regionally and globally, and the value of the Fund's assets may go down.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict such as between Russia and Ukraine or in the Middle East, terrorism, natural disasters, infectious illness or public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the Fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the Fund's investments may be negatively affected. The Fund may experience a substantial or complete loss on any security or investment.

Interest Rate Risk. The market prices of the Fund's fixed income securities may fluctuate significantly when interest rates change. The value of your investment will generally go down when interest rates rise. A rise in rates tends to have a greater impact on the prices of longer term or longer duration securities. In recent years, interest rates and credit spreads in the U.S. have been at historic lows. The U.S. Federal Reserve has raised certain interest rates, and interest rates may continue to go up. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the Fund. The maturity of a security may be significantly longer than its effective duration. A security's maturity and other features may be more relevant than its effective duration in determining the security's sensitivity to other factors such as changes in credit quality or in the yield premium that the market may establish for certain types of securities (sometimes called "credit spread"). In general, the longer its maturity the more a security may be susceptible to these factors. When the credit spread for a fixed income security goes up, or "widens," the value of the security will generally go down.

Credit Risk. If an issuer or obligor of a security held by the Fund or a counterparty to a financial contract with the Fund defaults or is downgraded, or is perceived to be less creditworthy, or if the value of the assets underlying a security declines, the value of your investment will typically decline. Changes in actual or perceived creditworthiness may occur quickly. The Fund could be delayed or hindered in its enforcement of rights against an issuer, guarantor or counterparty. Securities in the lowest category of investment grade (i.e., BBB/Baa) may be considered to have speculative characteristics.

Junk Bonds Risk. Junk bonds are considered speculative, have a higher risk of default, tend to be less liquid and are more difficult to value than higher grade securities. Junk bonds tend to be volatile and more susceptible to adverse events and negative sentiments.

Subordinated Securities Risk. Subordinated securities are more likely to suffer a credit loss than non-subordinated securities of the same issuer and will be disproportionately affected by a default, downgrade or perceived decline in creditworthiness.

Foreign Securities Risk. Foreign securities are subject to a number of additional risks, including nationalization or expropriation of assets, imposition of currency controls or restrictions, confiscatory taxation, political or financial instability, military conflicts and sanctions, terrorism, arbitrary application of laws and regulations or lack of rule of law, and other adverse economic or political developments. Lack of information and less market regulation may also affect the value of these securities. Risks are greater for investments in emerging markets. Emerging market countries tend to have economic, political and legal systems that are less fully developed and are less stable than those of more advanced countries. Low trading volumes may result in a lack of liquidity and in extreme price volatility. The value of

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investments in securities denominated in foreign currencies increases or decreases as the rates of exchange between those currencies and the U.S. dollar change. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation. Sanctions or other government actions against certain countries could negatively impact the Fund's investments in securities that have exposure to those countries. Circumstances that impact one country could have profound impacts on other countries and on global economies or markets.

Liquidity Risk. The Fund may make investments that are illiquid or become illiquid after purchase, including investments in securities issued in private placement transactions. Illiquid assets may also be difficult to value. Liquidity risk may be magnified in an environment of rising interest rates or widening credit spreads. If the Fund is forced to sell an illiquid security to meet redemption requests or other cash needs, the Fund may be forced to sell the security at a substantial loss or may not be able to sell at all. The Fund may not receive its proceeds from the sale of certain securities for an extended period (for example, several weeks or even longer). In extreme cases, this may constrain the Fund's ability to meet its obligations (including obligations to redeeming shareholders).

Prepayment or Call Risk. Many issuers have a right to prepay their securities. If interest rates fall, an issuer may exercise this right. If this happens, the Fund will not benefit from the rise in market price that normally accompanies a decline in interest rates, and will be forced to reinvest prepayment proceeds at a time when yields on securities available in the market are lower than the yield on prepaid securities. The Fund may also lose any premium it paid on prepaid securities.

Extension Risk. During periods of rising interest rates, repayments of fixed income securities may occur more slowly than anticipated by the market. This may drive the prices of these securities down even more because their interest rates are lower than the current interest rate and they remain outstanding longer.

Portfolio Selection Risk. The value of your investment may decrease if the Manager's judgment about the quality, relative yield, value or market trends affecting a particular market segment, security, industry, sector or region, or about interest rates or other market factors, is incorrect, or there may be imperfections, errors or limitations in the models, tools and information used by the Manager.

Valuation Risk. Nearly all of the Fund's investments are valued using a fair value methodology. The sales price the Fund could receive for any particular portfolio investment may differ from the Fund's valuation of the investment, particularly for securities that trade in thin or volatile markets. These differences may increase significantly and affect Fund investments more broadly during periods of market volatility. Investors who purchase or redeem Fund shares may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the securities had not been fair-valued or if a different valuation methodology had been used. The ability to value the Fund's investments may be impacted by technological issues and/or errors by pricing services or other third party service providers.

Redemption Risk. The Fund may experience heavy redemptions that could cause the Fund to liquidate its assets at inopportune times or at a loss or depressed value or accelerate taxable gains or transaction costs, which could cause the value of your investment to decline.

Cybersecurity Risk. Cybersecurity failures by and breaches of the Fund's Manager, Transfer Agent, Custodian, Distributor or other service providers may disrupt Fund operations, interfere with the Fund's ability to calculate its NAV, prevent Fund shareholders from purchasing, redeeming or exchanging shares or receiving distributions or receiving timely information regarding the Fund or their investment in the Fund, cause loss of or unauthorized access to private shareholder information, or result in financial losses to the Fund and its shareholders, regulatory fines, penalties, reputational damage, or additional compliance costs. Substantial costs may be incurred in order to prevent any cyber incidents in the future. The Fund and its shareholders could be negatively impacted as a result.

These risks are discussed in more detail in the Prospectus or in the SAI.

Fund Performance

The following bar chart and table provide some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns for the designated periods compare with those of a broad measure of market performance. No performance information is presented for Class F Shares because Class F Shares do not have annual returns for at least one calendar year. The returns for Class F Shares would differ from the returns shown because Class F Shares have different expenses. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance information is available at www.aquilafunds.com or by calling 800-437-1000 (toll-free).

Until September 30, 2021, Three Peaks Capital Management, LLC served as the sub-adviser of the Fund, and the Fund was known as "Aquila Three Peaks High Income Fund." Effective October 1, 2021, the Manager became directly responsible for portfolio management decisions for the Fund.

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During the 10-year period shown in the bar chart, the highest return for a quarter was 5.03% (quarter ended December 31, 2023) and the lowest return for a quarter was -7.02% (quarter ended June 30, 2022).

	Average Annual Total Returns for the Periods Ended December 31, 2023
	1 Year	5 Years	10 Years
Class Returns Before Taxes:
Class A	4.52%	3.39%	3.19%
Class C	7.08%	3.42%	2.79%
Class I	8.87%	4.14%	3.51%
Class Y	9.29%	4.46%	3.82%
Class Y Returns After Taxes:
On Distributions	7.20%	2.63%	1.93%
On Distributions and Redemption	5.44%	2.63%	2.08%
Bloomberg US Corporate High Yield Total Return Index Value Unhedged*	13.44%	5.37%	4.60%
(This index is unmanaged and does not reflect deductions for fund operating expenses or sales charges.)

*

Source: Bloomberg Index Services Limited. BLOOMBERG® is a trademark and service mark of Bloomberg Finance L.P. and its affiliates (collectively "Bloomberg"). Bloomberg, or Bloomberg's licensors, own all proprietary rights in the Bloomberg Indices. Neither Bloomberg nor Bloomberg's licensors approve or endorse this material or guarantee the accuracy or completeness of any information herein, nor does Bloomberg make any warranty, express or implied, as to the results to be obtained therefrom, and to the maximum extent allowed by law, neither shall have any liability or responsibility for injury or damages arising in connection therewith.

After-tax returns are calculated using the highest individual Federal marginal income and capital gains tax rates in effect at the time of each distribution and redemption, but do not reflect state and local taxes. Actual after-tax returns will depend on your specific situation and may differ from those shown. The after-tax returns shown are not relevant to investors who hold Fund shares through tax-deferred arrangements such as 401(k) plans or individual retirement accounts. The total returns reflect reinvestment of dividends and distributions. After-tax returns are shown only for Class Y Shares. After-tax returns for other classes of shares will vary.

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Management

Investment Adviser - Aquila Investment Management LLC

Portfolio Managers - Mr. David Schiffman is the Lead Portfolio Manager of the Fund since October 2021. He has 33 years of experience in the investment industry. Mr. Pedro Marcal, Director of Equities and High Yield at the Manager, is Co-Portfolio Manager of the Fund since October 2021. He has 30 years of experience in the investment industry.

Purchase and Sale of Fund Shares

You may purchase, redeem or exchange shares of the Fund on any day the New York Stock Exchange is open for business.

Shareholders that hold an Aquila Group of Funds account directly with the Funds may purchase, redeem and exchange shares of a Fund with the Fund's transfer and shareholder servicing agent through an online investor portal, which can be accessed via the Funds' website at aquilafunds.com/myaccount.

Shareholders may also purchase, redeem and exchange shares of a Fund in writing, by telephone or through a financial intermediary.

Shareholders may contact the Fund in writing or by telephone as follows:

·	U.S. Postal Service Mail: Aquila Group of Funds, P.O. Box 534428, Pittsburgh, PA 15253-4428

·	Overnight Carrier Deliveries: Aquila Group of Funds, Attention 534428, 500 Ross Street, 154-0520, Pittsburgh, PA 15262

·	The Fund's telephone number is 800-437-1000

The minimum initial purchase amount for Class A and Class C Shares is $1,000, or $50 if an automatic investment program is established. There is no minimum for subsequent investments.

Transactions in Class F Shares, Class I Shares and Class Y Shares may be made only through a financial intermediary, which may impose separate investment minimums.

Tax Information

The Fund intends to make distributions that may be taxed as ordinary income or capital gains.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of the Fund through a broker-dealer or other financial intermediary (such as a bank or financial advisor), the Fund and Aquila Distributors LLC (the "Distributor") or the Manager may pay the intermediary for the sale of Fund shares and related shareholder servicing activities. These payments create a conflict of interest by influencing the broker-dealer or other financial intermediary to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary's website for more information.

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AQL-HIFSPRO-0524

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