General Strategy Description.    The Fund invests at least 80% of its net assets in a portfolio of FLexible EXchange® Options (“FLEX Options”) that reference the SPDR® S&P 500® ETF Trust (the “Underlying ETF”), an exchange-traded fund registered under the Investment Company Act of 1940 (the “1940 Act”). The Underlying ETF seeks to track the investment results of the S&P 500 Index, a large-cap, market-weighted, U.S. equities index that tracks the performance of 500 leading companies in leading industries. To the extent the Underlying ETF concentrates (i.e., holds 25% or more of its total assets) in the securities of a particular industry or group of industries, the Fund will concentrate its investments to approximately the same extent. Through its use of FLEX Options on the Underlying ETF, the Fund has significant exposure to information technology companies.

Additional information about the Underlying ETF is set forth in the section entitled “Additional Information Regarding the Fund’s Principal Investment Strategies.” Due to the unique mechanics of the Fund’s strategy, the return an investor can expect to receive from an investment in the Fund has characteristics that are distinct from many other investment vehicles. It is important that an investor understand these characteristics before making an investment in the Fund.

In general, an option contract is an agreement between a buyer and seller that gives the purchaser of the option the right to buy or sell a particular asset at a specified future date at an agreed upon price. FLEX Options are exchange-traded options contracts with uniquely customizable terms. Although guaranteed for settlement by the Options Clearing Corporation (the “OCC”), FLEX Options are still subject to counterparty risk with the OCC and may be less liquid than more traditional exchange-traded options. Each of the FLEX Options purchased and sold throughout the Outcome Period are expected to have the same or similar terms (i.e., strike price and expiration) as the corresponding FLEX Options purchased and sold on the first day of the Outcome Period. The reference asset for all of the Fund’s FLEX Options is the Underlying ETF.

The pre-determined outcomes sought by the Fund, which include the buffer, accelerated return and cap discussed below (the “Outcomes”), are based upon the performance of the Underlying ETF’s share price over an approximately one-year period from October 1 through September 30 of the following year (the “Outcome Period”). The current Outcome Period is from October 1, 2023 through September30, 2024. Upon the conclusion of the Outcome Period, the Fund will receive the cash value of all the FLEX Options it held for the prior Outcome Period. It will then invest in a new series of FLEX Options with an expiration date in approximately one year, and a new Outcome Period will begin. The Outcomes may only be realized by investors who continuously hold Shares from the commencement of the Outcome Period until its conclusion. Investors who purchase Shares after the Outcome Period has begun, or sell Shares prior to the Outcome Period’s conclusion, may experience investment returns very different from those that the Fund seeks to provide.

The Outcomes.    The Fund’s strategy has been specifically designed to produce the Outcomes based upon the performance of the Underlying ETF’s share price (or its “price return”) over the duration of the Outcome Period. The Fund will not receive or benefit from any dividend payments made by the Underlying ETF. The Fund is not an appropriate investment for income-seeking investors. If the Underlying ETF’s share price increases over the duration of the Outcome Period,

the Fund seeks to provide investors who hold Shares for the entire Outcome Period with an increase in value that is twice the share price increase experienced by the Underlying ETF (the “Accelerated Return”), subject to an upside return cap discussed in greater detail below (the “Cap”). If the Underlying ETF’s share price decreases in value over the duration of the Outcome Period, the Fund seeks to provide Fund shareholders that hold Shares for the entire Outcome Period with an Outcome that provides for a buffer against the first 9% of Underlying ETF losses (the “Buffer”) prior to taking into account annual Fund management fees, shareholder transaction fees and any extraordinary expenses. The Fund’s shareholders will bear all Underlying ETF losses of greater than 9% on a one-to-one basis.There is no guarantee that the Fund will successfully provide the Outcomes.

The Fund seeks returns over an Outcome Period that generate twice the increased performance of the Underlying ETF, up to the Cap (as discussed in greater detail below), while limiting downside losses. The hypothetical graphical illustration provided below is designed to illustrate the Outcomes based upon the hypothetical performances of the Underlying ETF for investors who hold Shares for the entirety of the Outcome Period. There is no guarantee that the Fund will be successful in its attempt to provide the Outcomes for an Outcome Period. The returns that the Fund seeks to provide do not include the costs associated with purchasing Shares and certain expenses incurred by the Fund.

The following table contains hypothetical examples designed to illustrate the Outcomes the Fund seeks to provide over an Outcome Period, based upon the performance of the Underlying ETF from -100% to 100%. The table is provided for illustrative purposes and does not provide every possible performance scenario for Shares over the course of an Outcome Period.

There is no guarantee that the Fund will be successful in its attempt to provide the Outcomes for an Outcome Period. The table is not intended to predict or project the performance of the Underlying ETF, FLEX Options or the Fund. Fund shareholders should not take this information as an assurance of the expected performance of the Underlying ETF or return on Shares. The actual overall performance of the Fund during an Outcome Period will vary with fluctuations in the value of the FLEX Options during the Outcome Period, among other factors. Please refer to the Fund’s website, www.innovatoretfs.com/xboc, which provides updated information relating to this table on a daily basis throughout the Outcome Period.

*           The Cap is set on the first day of the Outcome Period and is 14.20% prior to taking into account any fees or expenses charged to shareholders. When the Fund’s annual management fee of 0.79% of the Fund’s average daily net assets is taken into account, the Cap is 13.41%. The Fund’s annual management fee of 0.79% of the Fund’s average daily net assets, any shareholder transaction fees and any extraordinary expenses incurred by the Fund will have the effect of reducing the Buffer and Cap amounts for Fund shareholders.

The Outcome Period.    The Outcomes sought by the Fund are based upon the Fund’s net asset value (“NAV”) at the outset of the Outcome Period. The Outcome Period begins on the day the FLEX Options are entered into and ends on the day they expire. Each FLEX Option’s value is ultimately derived from the performance of the Underlying ETF’s share price during that time. Because the terms of the FLEX Options don’t change, the Buffer, Accelerated Return and Cap relate to the Fund’s NAV on the first day of the Outcome Period. A shareholder that purchases Shares after the commencement of the Outcome Period will likely have purchased Shares at a different NAV than the NAV on the first day of the Outcome Period (the NAV upon which the Outcomes are based) and may experience investment outcomes very different from those sought by the Fund. A shareholder that sells Shares prior to the end of the Outcome Period may also experience investment outcomes very different from those sought by the Fund. To achieve the Outcomes sought by the Fund for the Outcome Period, an investor must be holding Shares at the time that the Fund enters into the FLEX Options and on the day those FLEX Options expire. There is no guarantee that the Fund will be successful in its attempt to provide the Outcomes.

The Fund’s assets will be principally composed of FLEX Options, the value of which is derived from the performance of the underlying reference asset, the Underlying ETF’s share price. The Fund’s investment sub-adviser, Milliman Financial Risk Management LLC (“Milliman” or the “Sub-Adviser”), generally anticipates that the Fund’s NAV will move in the same direction as the Underlying ETF’s share price. For example, during an Outcome Period, the Fund’s NAV is expected to increase if the Underlying ETF’s share price increases and decrease if the Underlying ETF’s share price decreases. However, it is unlikely that the Fund’s share price will increase or decrease at the same rate as the Underlying ETF’s share price and, for any given period during the Outcome Period, it is unlikely that the Fund’s share price will increase at the same rate as the Accelerated Return for the Outcome Period (i.e., an increase in value that is two times the share price change experienced by the Underlying ETF for an Outcome Period). In addition, if the Outcome Period has begun and the Fund has experienced any Accelerated Return, an investor purchasing Shares at that price may be subject to losses that exceed any losses of the Underlying

ETF for the remainder of the Outcome Period and may have diminished or no ability to experience further Accelerated Return. The Fund does not seek to provide investment outcomes on a daily or other short-term basis, but instead seeks to provide investment outcomes for the entire Outcome Period of one year. Prior to their expiration, the value of the Fund’s FLEX Options is not derived solely from the performance of the reference asset (the Underlying ETF), but a number of other factors as well, notably the number of days remaining until the options expire and the Accelerated Return available to the applicable Cap. These variables also affect the impact of the Buffer on the Fund’s NAV, which may not be in full effect prior to the end of the Outcome Period. As the number of days until the FLEX Options expire decreases, the value of the FLEX Options (and thus the Fund’s NAV) will more directly correlate with the returns experienced by the Underlying ETF and Outcomes the Fund seeks to provide for the Outcome Period. The Fund’s strategy is designed to produce the Outcomes upon the expiration of the FLEX Options on the last day of the Outcome Period. It should not be expected that the Outcomes will be provided at any point prior to that time, and there is no guarantee that the Outcomes will be achieved on the last day of the Outcome Period.

Potential Upside Accelerated Return Subject to a Cap.    If the Underlying ETF’s share price increases in value over the duration of the Outcome Period, the Fund’s strategy has been designed such that the Fund will experience an increase in value that is twice the increase experienced by the Underlying ETF, up to the Cap. The extent to which the Fund will participate in gains experienced by the Underlying ETF and the Accelerated Return is subject to the Cap that represents the maximum percentage return an investor can achieve from an investment in Shares over the duration of the Outcome Period. Therefore, even though the Fund’s returns, and any potential for the Accelerated Return, are based upon the performance of the Underlying ETF’s share price, if the Underlying ETF’s share price, or Accelerated Return, experiences returns for the Outcome Period in excess of the Cap, the Fund will not participate in excess returns. The Cap should be considered before investing in the Fund. The Fund’s returns, including any Accelerated Return, will not exceed the Cap. There is no guarantee that the Fund will successfully provide the Accelerated Return. If an investor is considering purchasing Shares during the Outcome Period, and the Fund has already increased in value to a level near to the Cap, an investor purchasing Shares at that price has limited to no gains and no Accelerated Return available for the remainder of the Outcome Period but remains vulnerable to significant downside risks. The Cap may rise or fall from one Outcome Period to the next.

The Cap will be determined on the first day of the Outcome Period based upon prevailing market conditions. Since the Cap is based upon prevailing market conditions at the beginning of an Outcome Period, the Cap will therefore rise or fall from one Outcome Period to the next. For the current Outcome Period, the Cap is set forth below, prior to taking into account annual Fund management fees, shareholder transaction fees and any extraordinary expenses.

•    The Cap is 14.20%.

When the Fund’s annual management fee of 0.79% of the Fund’s average daily net assets is taken into account, the Cap is revised downwards accordingly as set forth below and will be further reduced by any shareholder transaction fees and any extraordinary expenses incurred by the Fund.

•    The Cap is 13.41%.

For the purpose of this prospectus, “extraordinary expenses” are non-recurring expenses that may incurred by the Fund outside of the ordinary course of its business, including, without limitation, costs incurred in connection with any claim, litigation, arbitration, mediation, government investigation or similar proceedings, indemnification expenses and expenses in connection with holding and/or soliciting proxies for a meeting of Fund shareholders.

Buffer.    If the Underlying ETF’s share price decreases in value over the duration of the Outcome Period, the Fund’s strategy has been designed such that the Fund will experience a decrease in value that approximately matches the decrease experienced by the Underlying ETF, subject to the 9% Buffer. The Buffer is only operative against the first 9% of losses experienced by the Underlying ETF. This means that if the Underlying ETF’s share price decreases in value by up to 9% over the duration of the Outcome Period, the Fund seeks not to participate in any of those losses. However, if the Underlying ETF experiences losses in excess of 9% over the duration of the Outcome Period, the Fund’s shareholders will bear all losses exceeding 9% on a one-to-one basis. A shareholder that purchases Shares at the beginning of the Outcome Period may lose their entire investment. While the Fund seeks to limit losses to 91% for shareholders who hold Shares for the entire Outcome Period, there is no guarantee it will successfully do so. Depending upon market conditions at the time of purchase, a shareholder that purchases Shares after the Outcome Period has begun may also lose their entire investment. Furthermore, if the Outcome Period has begun and the Fund has experienced any Accelerated Return, an investor purchasing Shares at that price may be subject to losses that exceed any losses of the Underlying ETF until the remainder of the Outcome Period.An investment in the Fund is only appropriate for shareholders willing to bear those losses. If an investor is considering purchasing Shares during the Outcome Period, and the Fund has already decreased in value by an amount equal to or greater than 9%, an investor purchasing Shares at that price will have increased gains available prior to reaching the Cap but may not benefit from the Buffer that the Fund seeks to offer for the remainder of the Outcome Period. Conversely, if an investor is considering purchasing Shares during the Outcome Period, and the Fund has already increased in value, then a shareholder may experience losses prior to gaining the protection offered by the Buffer. There is no guarantee that the Fund will be successful in its attempt to provide buffered returns.

The Buffer is provided prior to taking into account annual Fund management fees, shareholder transaction fees and any extraordinary expenses incurred by the Fund. These fees and any expenses will have the effect of reducing the Buffer amount for Fund shareholders for an Outcome Period. When the Fund’s annual management fee equal to 0.79% of the Fund’s daily net assets is taken into account, the net Buffer for an Outcome Period is 8.21%.

Use of FLEX Options.    The Outcomes described above may be achieved by purchasing and selling call and put FLEX Options to create layers within the Fund’s portfolio. The Sub-Adviser has constructed a portfolio principally composed of FLEX Options that reference the Underlying ETF that are each set to expire on the last day of the Outcome Period. The customizable nature of FLEX Options allows the Sub-Adviser to select the share price at which the Underlying ETF will be exercised at the expiration of each FLEX Option. This is commonly known as the “strike price.” At the commencement of the Outcome Period, the Sub-Adviser specifically selects the strike price for each FLEX Option such that when the FLEX Options are exercised on the final day of the Outcome Period, the Outcomes may be obtained, depending on the performance of the Underlying ETF’s share price over the duration of the Outcome Period.

To achieve these returns, the Fund may purchase a combination of call options (giving the Fund the right to receive the cash value of the Underlying ETF’s share price) and put options (giving the Fund the right to deliver the cash value of the Underlying ETF’s share price), while simultaneously selling call options (giving the Fund the obligation to deliver the cash value of the Underlying ETF’s share price) and put options (giving the Fund the obligation to receive the cash value of the Underlying ETF’s share price). Each of these FLEX Options has a specifically selected strike price.

A detailed explanation regarding the terms of the FLEX Options and the mechanics of the Fund’s strategy can be found in “Additional Information About the Fund’s Principal Investment Strategies.”

Fund Rebalance.    The Fund is a continuous investment vehicle. It does not terminate and distribute its assets at the conclusion of each Outcome Period. On the termination date of an Outcome Period, the Sub-Adviser will invest in a new set of FLEX Options and another Outcome Period will commence.

Approximately one week prior to the end of each Outcome Period, the Fund will file a prospectus supplement, which will alert existing shareholders that an Outcome Period is approaching its conclusion and disclose the anticipated ranges for the Cap for the next Outcome Period. Following the close of business on the last day of the Outcome Period, the Fund will file a prospectus supplement that discloses the Fund’s final Cap (both gross and net of the unitary management fee) for the next Outcome Period. This information is available on the Fund’s website, www.innovatoretfs.com/xboc, which also provides information relating to the Outcomes, including the Fund’s position relative to the Cap, of an investment in the Fund on a daily basis.

The Fund is classified as “non-diversified” under the Investment Company Act of 1940, as amended (the “1940 Act”).