SUMMARY PROSPECTUS

APRIL 30, 2024

CLASS N SHARES
Nicholas II, Inc. - NNTWX

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 www.nicholasfunds.com/prospectus.html. You can also get this information at no cost by calling 800-544-6547 or by sending an e-mail request to [email protected]. This Summary Prospectus incorporates by reference the Fund's Prospectus, dated April 30, 2024 and Statement of Additional Information, dated April 30, 2024.

Investment Objective

The Fund strives to increase the value of your investment over the long-term ("long-term growth").

Fees and Expenses of the Fund

The table below describes the fees and expenses that you may pay if you buy and hold 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.

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.

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 in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 6.26% of the average value of the portfolio.

Principal Investment Strategies

To pursue the Fund's investment objective of long-term growth, it primarily invests in common stocks of domestic corporations with medium-sized market capitalizations believed to have growth potential. The Fund believes a company's annual sales volume and the market capitalization (the number of shares outstanding multiplied by the per share price) are the factors most illustrative of a company's size. In distinguishing company size in terms of sales volume, the Fund considers a company's sales volume relative to peer companies in the company's industry. In terms of market capitalization, the Fund generally considers companies with market capitalizations up to $3 billion as "small," between $3 billion and $25 billion as "medium," and greater than $25 billion as "large." To a lesser extent, the Fund may invest in companies with small and large market capitalizations. The Fund looks for established companies with the potential for superior growth in sales and earnings in a diversified group of industries. The Fund's investment philosophy is basically a long-term growth philosophy, based upon the assumption that if a company achieves superior growth in sales and earnings, eventually the company's stock will achieve superior performance. It is anticipated that a major portion of the Fund's portfolio will be invested in common stocks of the types of companies, and in the manner, as described above.

Principal Risks of Investing

As with any mutual fund, the Fund cannot guarantee that it will achieve its goals or that its performance will be positive over any period of time. The Fund's investments change in value. Consequently, the value of your Fund shares may change. If the value of the Fund shares or the values of the Fund's investments go down, you may lose money.

The principal risks of investing in the Fund are:

• Market Risk - Market risk involves the possibility that the value of the Fund's investments willfluctuate as the stock market fluctuates over short- or longer-term periods. Common stock pricestend to be more volatile than other investment choices.

• Portfolio-Specific Risk - From time to time, the value of an individual company may decline dueto a particular set of circumstances affecting that company, its industry or certain companieswithin the industry, while having little or no impact on other similar companies within theindustry. Because the Fund will invest most of its assets in the securities of mid-cap companiesand to a lesser extent, small-cap companies, the Fund may face additional risks. Small- to mid-cap companies often have a limited market for their securities and limited financial resources, andare usually more affected by changes in the economy. Securities of small to mediumcapitalization companies also often fluctuate in price more than common stocks of largercapitalization companies.

• Selection Risk - The Fund also faces selection risk, which is the risk that the stocks the Fundpurchases will underperform markets or other mutual funds with similar investment objectivesand strategies.

• Public Health Threats Risk - Threats to public health can have a negative impact on the globaleconomy and financial markets, which could adversely affect the securities held by the Fund.
  Impacts of public health threats may last for an extended period of time and result in a substantialeconomic downturn. Health crises caused by outbreaks may exacerbate other pre-existing political,social and economic risks and disrupt normal market conditions and operations. The impact of thisoutbreak, and other epidemics and pandemics that may arise in the future, could negatively affectthe worldwide economy, as well as the economies of individual countries, individual companiesand the market in general in significant and unforeseen ways. These developments as well as other

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• events could result in further market volatility and negatively affect security prices, the liquidity ofcertain securities and the normal operations of securities exchanges and other markets. As a result,the risk environment remains elevated. The Adviser will monitor developments and seek tomanage the Fund in a manner consistent with achieving the Fund's investment objective, but therecan be no assurance that it will be successful in doing so.

• Cybersecurity Risk - The Fund, its service providers, and third party fund distribution platforms,and your ability to transact with the Fund, may be negatively impacted due to operational risksarising from, among other issues, human errors, systems and technology disruptions or failures, orcybersecurity incidents. Cybersecurity incidents may allow an unauthorized party to gain access tofund assets, customer data, or proprietary information, or cause the Fund or its service providers,as well as the securities trading venues and their service providers, to suffer data corruption or loseoperational functionality. The occurrence of any of these issues could result in a loss ofinformation, regulatory scrutiny, reputational damage and other consequences, any of which couldhave a material adverse effect on the Fund or its shareholders. Cybersecurity incidents could alsoaffect issuers of securities in which the Fund invests, leading to significant loss of value.

Since there are risks inherent in all investments in securities, there is no assurance that the Fund's objectives will be achieved.

Performance

The bar chart shown below provides some indication of the risks of investing in the Fund. The chart shows the variability of the total return of the Fund's shares for the last ten calendar years⁽¹⁾. Updated performance information for the Fund is available on our website at www.nicholasfunds.com.

Nicholas II, Inc. - Class N

For the ten calendar year periods shown in the above bar chart, the highest quarterly return was 23.90% (for the quarter ended June 30, 2020) and the lowest quarterly return was -23.41% (for the quarter ended March 31, 2020).

This next table shows how the average annual total returns for the one, five and ten year periods ending on December 31, 2023 (the Fund's most recently completed calendar year), compared to the returns of broad measures of market performance and the performance average of similar mutual funds. The table also shows the average annual total returns for the Fund after taxes on distributions and after taxes on distributions and the redemption of all of your Fund shares. 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 depend on an investor's tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. Updated performance information for the Fund is available on our website at www.nicholasfunds.com.

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Of course, the Fund's past performance (before and after taxes) is no guarantee of its future returns.

Investment Adviser

Nicholas Company, Inc. serves as the Fund's investment adviser (the "Adviser").

Portfolio Managers

Mr. David O. Nicholas is President, a Director and Lead Portfolio Manager of the Fund and is primarily responsible for the day-to-day management of the Fund's portfolio. Mr. Nicholas has been Portfolio Manager of the Fund since 1993. Mr. Brian J. Janowski, Senior Vice President of the Fund, has been Co-Portfolio Manager of the Fund since April 2018.

Purchase and Sale of Fund Shares

The minimum initial investment for the Class N shares of the Fund is $500. The minimum subsequent investment is $100 except for those shareholders participating in an automatic investment plan established with the Fund, the minimum is $50.

The Fund's shares are redeemable. Generally, shareholders may redeem some or all of their shares without charge by the Fund on any day when the New York Stock Exchange is open by written request, by telephone request by calling 800-544-6547, by accessing your account online at www.nicholasfunds.com or by wire transfer.

Tax Information

Shareholders may receive distributions from the Fund of ordinary income dividends and capital gains, which may be taxable to shareholders.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank or financial adviser), the Fund and its related companies may pay that intermediary for the sale of Fund shares and related services. Please bear in mind that these payments may create a conflict of interest by influencing the broker-dealer or other intermediary to recommend the Fund over another investment. Ask your intermediary or visit your intermediary's website for more information.

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