Discount Opportunity Strategy Portfolio of CEFs Series 21

The trust will invest in common shares of closed-end investment companies (“Closed-End Funds”) that are currently trading at a greater percentage discount to their net asset value (“NAV Discount”) than their historical NAV Discount. The trust seeks capital appreciation by selecting Closed-End Funds that the sponsor believes have the potential to narrow the gap between their current NAV Discount and their historical NAV Discount. The trust portfolio will include a variety of Closed-End Funds, including general equity funds, taxable fixed-income funds, municipal funds and balanced/multi-asset funds. The Closed-End Funds will invest in securities of a variety of asset classes. These asset classes may include, but are not limited to:

• high-yield securities or “junk” bonds;
• convertible securities;
• preferred securities;
• real estate investment trusts (“REITs”);
• senior loans;
• corporate bonds;
• government bonds;
• municipal bonds;
• options;
• foreign securities, including securities of companies located in emerging markets; and
• equities.

The Sponsor, with the assistance of Guggenheim Partners Investment Management, LLC (“GPIM”), an affiliate of Guggenheim Partners, LLC, has selected the securities to be included in the Trust’s portfolio according to the selection criteria described below.

The security selection process begins by identifying the entire universe of Closed-End Funds listed on a U.S. public securities exchange as provided by Morningstar. As of the security selection date, each Closed-End Fund is then ranked by:

• Current NAV Discount versus historic monthly NAV Discounts, a metric commonly referred to as a “Z-Score.” The lowest “Z-Score” values represent the deepest discounts relative to prior range of discounts, and also represent the highest rank.
• Trailing six month total return, where the highest values represent the highest rank.

Closed-End Funds with better ranks will be considered more strongly for inclusion in the Trust, subject to the Sponsor’s discretion. In addition, the Trust will be subject to the following constraints (as measured on the security selection date). For the constraints that reference Closed-End Fund classifications, the “Asset Category” and “Classification” attributes are sourced from Morningstar Traded Fund Center (formerly FundData).

• Exclude Closed-End Funds in the initial universe ranked in the worst 20% in any of the following three metrics: (i) current NAV Discount, where lower values rank better, (ii) “Z-score,” where lower “Z-score” values rank higher, or (iii) trailing six month total return, as sourced from FactSet, where the highest values represent the highest rank;
• No more than 60% in Closed-End Funds with “Asset Category” of “Equity”;
• No more than 60% in Closed-End Funds with “Asset Category” of “Taxable Fixed Income”;
• No more than 20% in Closed-End Funds with “Asset Category” of “Municipal”;
• No more than 30% in Closed-End Funds with “Asset Category” of “Hybrid (Growth & Income)”;
• No more than 25% in Closed-End Funds with the same “Classification”;
• Exclude securities with trading liquidity of less than $400,000 (or less than the median trading liquidity of the entire Closed-End Fund starting universe if that is less than $400,000). Trading liquidity is measured by the median daily dollar volume (daily volume times closing daily price) over the prior 30 trading days, as sourced from FactSet; and
• Exclude Closed-End Funds advised by the Sponsor or its affiliates.

Final Trust selections will be influenced by the rankings and constraints described above as well as the Sponsor’s outlook for an individual fund and/or Closed-End Fund marketplace. Closed-End Funds selected for the portfolio will be equally-weighted as of the selection date. Please note that due to the fluctuating nature of security prices, the weighting of an individual security or sector in the Trust portfolio may change after the selection date.

Some of the securities held by the Closed- End Funds are income-producing securities, including corporate bonds, preferred securities and high-yield bonds. These securities held by the Closed-End Funds may have fixed or floating rates. High-yield or “junk” bonds, the generic names for bonds rated below investment-grade, are frequently issued by corporations in the growth stage of their development or by established companies who are highly leveraged or whose operations or industries are depressed. Obligations rated Investment below investment-grade should be considered speculative as these ratings indicate a quality of less than investment-grade. Because high-yield bonds are generally subordinated obligations and are perceived by investors to be riskier than higher rated securities, their prices tend to fluctuate more than higher rated securities and are affected by short-term credit developments to a greater degree.

As with all investments, you may lose some or all of your investment in the Trust. No assurance can be given that the Trust’s investment objective will be achieved. The Trust also might not perform as well as you expect. This can happen for reasons such as these:

• Securities prices can be volatile. The value of your investment may fall over time. Market value fluctuates in response to various factors. These can include stock market movements, purchases or sales of securities by the Trust, government policies, litigation, and changes in interest rates, inflation, the financial condition of the securities’ issuer or even perceptions of the issuer. Changes in legal, political, regulatory, tax and economic conditions may cause fluctuations in markets and securities prices, which could negatively impact the value of the Trust. Additionally, event such war, terrorism, natural and environmental disasters and the spread of infectious illnesses or other public health emergencies may adversely affect the economy, various markets and issuers. Recently, the outbreak of a novel and highly contagious form of coronavirus (“COVID-19”) has adversely impacted global commercial activity and contributed to significant volatility in certain markets. Many governments and businesses have instituted quarantines and closures, which has resulted in significant disruption in manufacturing, supply chains, consumer demand and economic activity. The potential impacts are increasingly uncertain, difficult to assess and impossible to predict, and may result in significant losses. Any adverse event could materially and negatively impact the value and performance of Trust and the Trust’s ability to achieve its investment objectives. Units of the Trust are not deposits of any bank and are not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
• The Trust includes Closed-End Funds. Closed-End Funds are actively managed investment companies that invest in various types of securities. Closed-End Funds issue common shares that are traded on a securities exchange. Closed-End Funds are subject to various risks, including management’s ability to meet the Closed-End Fund’s investment objective and to manage the Closed- End Fund’s portfolio during periods of market turmoil and as investors’ perceptions regarding Closed-End Funds or their underlying investments change. Closed-End Funds are not redeemable at the option of the shareholder and they may trade in the market at a discount to their net asset value. Closed-End Funds may also employ the use of leverage which increases risk and volatility.
• The Closed-End Funds are subject to annual fees and expenses, including a management fee. Unitholders of the Trust will bear these fees in addition to the fees and expenses of the Trust. See “Fees and Expenses” for additional information.
• The value of the fixed-income securities in the Closed-End Funds will generally fall if interest rates, in general, rise. Typically, fixed-income securities with longer periods before maturity are more sensitive to interest rate changes. The Trust may be subject to greater risk of rising interest rates than would normally be the case due to the current period of historically low rates.
• A Closed-End Fund or an issuer of securities held by a Closed-End Fund may be unwilling or unable to make principal payments and/or to declare distributions in the future, may call a security before its stated maturity, or may reduce the level of distributions declared. A Closed-End Fund or an issuer may suspend distributions during the life of the Trust. This may result in a reduction in the value of your units.
• The financial condition of a Closed- End Fund or an issuer of securities held by a Closed-End Fund may worsen, resulting in a reduction in the value of your units. This may occur at any point in time, including during the primary offering period. As the Trust is unmanaged, a downgraded security will remain in the portfolio.
• Certain Closed-End Funds held by the Trust invest in convertible securities. Convertible securities generally offer lower interest or dividend yields than non-convertible fixed-income securities of similar credit quality because of the potential for capital appreciation. The market values of convertible securities tend to decline as interest rates increase and, conversely, to increase as interest rates decline. However, a convertible security’s market value also tends to reflect the market price of the common stock of the issuing company, particularly when that stock price is greater than the convertible security’s “conversion price.” Convertible securities fall below debt obligations of the same issuer in order of preference or priority in the event of a liquidation and are typically unrated or rated lower than such debt obligations.
• Certain Closed-End Funds held by the Trust invest in foreign securities. Investment in foreign securities presents additional risk. Foreign risk is the risk that foreign securities will be more volatile than U.S. securities due to such factors as adverse economic, currency, political, social or regulatory developments in a country, including government seizure of assets, excessive taxation, limitations on the use or transfer of assets, the lack of liquidity or regulatory controls with respect to certain industries or differing legal and/or accounting standards.
• Certain Closed-End Funds held by the Trust may invest in securities issued by small-capitalization and mid-capitalization companies. These securities customarily involve more investment risk than securities of large-capitalization companies. Small-capitalization and mid-capitalization companies may have limited product lines, markets or financial resources and may be more vulnerable to adverse general market or economic developments.
• Economic conditions may lead to limited liquidity and greater volatility. The markets for fixed-income securities, such as those held by certain Closed-End Funds, may experience periods of illiquidity and volatility. General market uncertainty and consequent repricing risk have led to market imbalances of sellers and buyers, which in turn have resulted in significant valuation uncertainties in a variety of fixed-income securities. These conditions resulted, and in many cases continue to result in, greater volatility, less liquidity, widening credit spreads and a lack of price transparency, with many debt securities remaining illiquid and of uncertain value. These market conditions may make valuation of some of the securities held by a Closed-End Fund uncertain and/or result in sudden and significant valuation increases or declines in its holdings.
• The Trust may be susceptible to potential risks through breaches in cybersecurity. A breach in cybersecurity refers to both intentional and unintentional events that may cause the Trust to lose proprietary information, suffer data corruption or lose operational capacity. Such events could cause the Sponsor of the Trust to incur regulatory penalties, reputational damage, additional compliance costs associated with corrective measures and/or financial loss. In addition, cybersecurity breaches of the Trust’s third-party service providers, or issuers in which the Trust invests, can also subject the Trust to many of the same risks associated with direct cybersecurity breaches.
• The Trust is subject to risks arising from various operational factors and their service providers. Operational factors include, but not limited to, human error, processing and communication errors, errors of the Trust’s service providers, counterparties or other third-parties, failed or inadequate processes and technology or systems failures. Additionally, the Trust may be subject to the risk that a service provider may not be willing or able to perform their duties as required or contemplated by their agreements with the Trust. Although the Trust seeks to reduce these operational risks through controls and procedures, there is no way to completely protect against such risks.
• Inflation may lead to a decrease in the value of assets or income from investments.
• The Sponsor does not actively manage the portfolio. The Trust will generally hold, and may, when creating additional units, continue to buy, the same securities even though a security’s outlook, market value or yield may have changed.

See “Investment Risks” in Part A of the prospectus and “Risk Factors” in Part B of the prospectus for additional information.