Senior Loan & Limited Duration Opportunities Closed-End, Series 66

As interest rates remain low, these are challenging times to invest for income. In this environment, many investors are seeking alternative sources of income, including those which tend to be less rate-sensitive than other segments of the bond market, such as senior loans and limited duration bonds.

Portfolio Objective

This unit investment trust seeks high current income by investing in a diversified portfolio of closed-end funds which invest in senior loan and limited duration fixed-income securities; however, there is no assurance the objective will be met.

Consider These Factors

• While senior loans are generally loans which have been made to companies whose debt is typically rated below investment grade, they are senior in the asset structure of a company and historical recovery rates in the event of a default tend to be much higher relative to junior high-yield corporate debt.
• We believe that senior loans can be used as an effective means to aid portfolio diversification because of their low correlation to other fixed-income asset classes. Correlation is a statistical measure that provides a way to evaluate the potential diversification benefits of combining different assets. The historical correlation between senior loans and other asset classes, including investment-grade corporate bonds and equities, is low. Because senior loans are not highly correlated with other asset classes, they can potentially decrease portfolio volatility, enhance overall return and provide meaningful diversification to an asset allocation strategy. It is important to note that diversification does not guarantee a profit or protect against loss.
• Limited duration closed-end funds provide investors with the potential for high income but with less interest rate sensitivity. The duration of a bond is a measure of its price sensitivity to interest rate movements based on the weighted average term to maturity of its interest and principal cash flows.
• Limited duration closed-end funds are typically diversified across several different segments of the fixed income market. This multi-sector income approach primarily helps to reduce volatility and also has the potential to enhance your returns because different sectors within the debt market often react differently to economic and market changes.

Closed-End Features

Portfolio Control
Since closed-end funds maintain a relatively fixed pool of investment capital, portfolio managers are better able to adhere to their investment philosophies through greater flexibility and control. In addition, closed-end funds don’t have to manage fund liquidity to meet potentially large redemptions.

Income Distributions
Closed-end funds are structured to generally provide a more stable income stream than other managed investment products because they are not subjected to cash inflows and outflows, which can dilute dividends over time. However, as a result of bond calls, redemptions and advanced refundings, which can dilute a fund’s income, the portfolio cannot guarantee consistent income.

You should consider the portfolio's investment objectives, risks, and charges and expenses carefully before investing. Contact your financial advisor or call First Trust Portfolios, L.P. at 1.800.621.1675 to request a prospectus, which contains this and other information about the portfolio. Read it carefully before you invest.

Risk Considerations
An investment in this unmanaged unit investment trust should be made with an understanding of the risks associated with senior loan and limited duration closed-end funds.

Closed-end funds are subject to various risks, including management’s ability to meet the fund’s investment objective, and to manage the fund’s portfolio when the underlying securities are redeemed or sold, during periods of market turmoil and as investors’ perceptions regarding the funds or their underlying investments change. Unlike open-end funds, which trade at prices based on a current determination of the fund’s net asset value, closed-end funds frequently trade at a discount to their net asset value in the secondary market. Certain of the closed-end funds employ the use of leverage, which increases the volatility of such funds.

Certain of the closed-end funds invest in floating-rate securities. A floating-rate security is an instrument in which the interest rate payable on the obligation fluctuates on a periodic basis based upon changes in an interest rate benchmark. As a result, the yield on such a security will generally decline in a falling interest rate environment, causing the trust to experience a reduction in the income it receives from such securities. Certain of the floating-rate securities pay interest based on LIBOR. Due to the uncertainty regarding the future utilization of LIBOR and the nature of any replacement rate, the potential effect of a transition away from LIBOR on a fund or the financial instruments in which the fund invests cannot yet be determined.

All of the closed-end funds invest in high-yield securities or “junk” bonds. Investing in high-yield securities should be viewed as speculative and you should review your ability to assume the risks associated with investments which utilize such securities. High-yield securities are subject to numerous risks, including higher interest rates, economic recession, deterioration of the junk bond market, possible downgrades and defaults of interest and/or principal. High-yield security prices tend to fluctuate more than higher rated securities and are affected by short-term credit developments to a greater degree.

Certain of the closed-end funds invest in limited duration bonds. Limited duration bonds are subject to interest rate risk, which is the risk that the value of a security will fall if interest rates increase. While limited duration bonds are generally subject to less interest rate sensitivity than longer duration bonds, there can be no assurance that interest rates will not rise during the life of the trust.

Certain of the closed-end funds invest in senior loans. The yield on closed-end funds which invest in senior loans will generally decline in a falling interest rate environment and increase in a rising interest rate environment. Senior loans are generally below investment grade quality (“junk” bonds). An investment in senior loans involves the risk that the borrowers may default on their obligations to pay principal or interest when due.

Certain of the closed-end funds invest in covenant-lite loans which contain fewer or no maintenance covenants and may hinder the closed-end fund’s ability to reprice credit risk and mitigate potential loss especially during a downturn in the credit cycle.

All of the closed-end funds invest in securities issued by foreign issuers. Such securities are subject to certain risks including currency and interest rate fluctuations, nationalization or other adverse political or economic developments, lack of liquidity of certain foreign markets, withholding, the lack of adequate financial information, and exchange control restrictions impacting foreign issuers.

As the use of Internet technology has become more prevalent in the course of business, the trust has become more susceptible to potential operational risks through breaches in cybersecurity.

The value of the securities held by the trust may be subject to steep declines or increased volatility due to changes in performance or perception of the issuers.

It is important to note that an investment can be made in the underlying funds directly rather than through the trust. These direct investments can be made without paying the trust’s sales charge, operating expenses and organizational costs.

Although this portfolio terminates in approximately 15 months, the strategy is long-term. Investors should consider their ability to pursue investing in successive portfolios, if available. There may be tax consequences unless units are purchased in an IRA or other qualified plan.

For a discussion of additional risks of investing in the trust see the “Risk Factors” section of the prospectus.