Dec. 29, 2022

BARRETT OPPORTUNITY FUND, INC.

Barrett Opportunity Fund, Inc.

Investment Objectives

Barrett Opportunity Fund, Inc. (the “Fund”) seeks to achieve above average long-term capital appreciation.

Current income is a secondary objective.

Fees and Expenses of the Fund

The table below 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 table and example below.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees

(fees paid directly from your investment)

None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

Management Fees	0.70%
Distribution and Service (12b-1) Fees	None
Other Expenses	0.48%
Total Annual Fund Operating Expenses	1.18%

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:

•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

•Your investment has a 5% return each year and the Fund’s operating expenses remain the same

You would incur these hypothetical expenses whether or not you redeem your investment at the end of the given period.

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
$120	$375	$649	$1,432

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 may generate higher transaction costs and may result in higher taxes when shares are held in a taxable account. These transaction costs and potentially higher taxes, 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 8% of the average value of its portfolio.

Principal Investment Strategies

The Fund’s investment objectives are not fundamental and may be changed by the Board of Directors upon 60 days’ written notice to holders of the Fund’s common shares.

The Fund invests primarily in common stocks and securities convertible into or exchangeable for common stock such as convertible preferred stock or convertible debt securities.

The Fund may also invest without limit in fixed-income securities (including up to 5% of its net assets in fixed-income securities that are high yield, lower quality securities rated by a rating organization below its top four long-term rating categories (i.e., below investment grade securities, commonly referred to as “junk bonds”)) or unrated securities determined by the Adviser (as defined below) to be of equivalent quality.

The Fund is non-diversified.

Principal Risks

Risk is inherent in all investing. There is no assurance that the Fund will meet its investment objectives. The value of your investment in the Fund, as well as the amount of return you receive on your investment, may fluctuate significantly. You may lose part or all of your investment in the Fund or your investment may not perform as well as other similar investments. The following is a summary description of certain risks of investing in the Fund.

Stock market and equity securities risk. The securities markets are volatile and the market prices of the Fund’s securities may decline generally. Securities fluctuate in price based on changes in a company’s financial condition and overall market and economic conditions, which are difficult to predict accurately. If the market prices of the securities owned by the Fund fall, the value of your investment in the Fund will decline.

Issuer risk. The value of a security can go up or down more than the market as a whole and can perform differently from the value of the market as a whole, often due to events such as (but not limited to) disappointing earnings reports by the issuer, unsuccessful products or services, loss of major customers, major litigation against the issuer or changes in government regulations affecting the issuer or the competitive environment. The Fund may experience a substantial or complete loss on an individual security. Historically, the prices of securities of small- and medium-capitalization companies have generally gone up or down more than those of large capitalization companies because, among other things, small- and medium-capitalization companies may be more sensitive to changing economic conditions and tend to be less established than large capitalization companies, although even large capitalization companies may fall out of favor with investors.

Portfolio selection risk. The value of your investment may decrease if the portfolio managers’ judgment about the attractiveness, value or market trends affecting a particular security, industry or sector or about market movements is incorrect.

Non-diversification risk. The Fund is classified as “non-diversified,” which means it may invest a larger percentage of its assets in a smaller number of issuers than a diversified fund. To the extent the Fund invests its assets in fewer issuers, the Fund will be more susceptible to negative events affecting those issuers.

Net unrealized appreciation. The Fund currently has a substantial amount of net unrealized appreciation. At November 30, 2022, the amount of the net unrealized appreciation was $43,625,546, representing approximately 72% of the Fund’s net assets. The Adviser no longer pursues a strategy of retaining unrealized long-term capital gain and avoiding the tax impact of realizing such gain. Subject to market conditions and Fund performance, the Adviser anticipates that, in managing the Fund’s investment portfolio in pursuit of the Fund’s investment objectives, a moderate portion of the Fund’s current built-in long-term capital gains will be realized gradually in each of the next several years. If these long-term capital gains are realized as anticipated, this will result in an increase in the Fund’s annual distributions of net capital gains and, accordingly, will generally result in taxable distributions to shareholders (other than certain shareholders that are exempt from tax on such income). Under normal market conditions, the Adviser currently expects, but does not guarantee, that no more than 15% of the total amount of the Fund’s current built-in long-term capital gains will be realized in any one year. This expectation may change over the course of the year for a variety of reasons including, but not limited to, individual holdings, market events and changes in tax laws. See “Dividends, Distributions and Taxes.”

Value investing risk. The value approach to investing involves the risk that stocks may remain undervalued. Value stocks may underperform the overall equity market. Although the Fund will not concentrate its investments in any one industry or industry group, it may, like many value funds, weight its

investments toward certain industries, thus increasing its exposure to factors adversely affecting issuers within those industries. Accordingly, the Fund’s performance may be disproportionately affected by the poor performance of a certain industry.

Large capitalization company risk. Historically, the prices of securities of small- and medium-capitalization companies have generally fluctuated more than those of large capitalization companies because, among other things, small- and medium-capitalization companies may be more sensitive to changing economic conditions and tend to be less established, however, large capitalization companies may fall out of favor with investors.

Small- and medium-capitalization company risk. The Fund will be exposed to additional risks as a result of its investments in the securities of small- and medium-capitalization companies. Small- and medium-capitalization companies may fall out of favor with investors; may have limited product lines, operating histories, markets or financial resources; or may be dependent upon a limited management group. The prices of securities of small- and medium-capitalization companies generally are more volatile than those of large capitalization companies and are more likely to be adversely affected than large capitalization companies by changes in earnings results and investor expectations or poor economic or market conditions, including those experienced during a recession. Securities of small- and medium-capitalization companies may underperform large capitalization companies, may be harder to sell at times and at prices the portfolio manager believes appropriate and may offer greater potential for losses.

Covered Call Risk. The primary risk to the Fund as the writer of a covered call option is that, unless a closing transaction is executed, the Fund must retain its underlying cover position even if price movement would otherwise have caused the Fund to dispose of that position and must forgo opportunities for gain in excess of the option premium that may result from favorable changes in the value of the underlying cover position.

Foreign investments risk. The Fund’s investments in securities of foreign issuers involve greater risk than investments in securities of U.S. issuers. Foreign countries in which the Fund may invest may have markets that are less liquid and more volatile than U.S. markets and may suffer from political or economic instability. In some foreign countries, less information is available about issuers and markets because of less rigorous accounting, legal and regulatory standards than in the United States. Currency fluctuations could erase investment gains or add to investment losses. Income earned on foreign securities may be subject to foreign withholding taxes.

Recent market events risk. U.S. and international markets have experienced significant periods of volatility in recent years due to a number of economic, political and global macro factors including the impact of the coronavirus (COVID-19) as a global pandemic which has resulted in public health issues, growth concerns in the U.S. and overseas, layoffs, rising unemployment and reduced consumer spending. The effects of COVID-19 may lead to a substantial economic downturn or recession in the U.S. and global economies, the recovery from which is uncertain and may last for an extended period of time.

Cybersecurity risk. With the increased use of technologies such as the Internet to conduct business, the Fund is susceptible to operational, information security, and related risks. Cyber incidents affecting the Fund or its service providers may cause disruptions and impact business operations, potentially resulting in financial losses, interference with the Fund’s ability to calculate its NAV, impediments to trading, the inability of shareholders to transact business, violations of applicable privacy and other laws, regulatory fines, penalties, reputational damage, reimbursement or other compensation costs, or additional compliance costs.

Risk of increase in expenses. Your actual costs of investing in the Fund may be higher than the expenses shown in “Annual Fund Operating Expenses” under “Fees and Expenses of the Fund” for a variety of reasons. For example, expense ratios may be higher than those shown if average net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are

volatile. Additionally, a higher portfolio turnover may indicate higher transaction costs and may result in higher taxes when shares are held in a taxable account.

These risks are discussed in more detail later in this Prospectus and in the Statement of Additional Information (the “SAI”).

Performance

The accompanying bar chart and table provide some indication of the risks of investing in the Fund. The bar chart shows changes in the Fund’s performance from year to year. The table shows the average annual total returns of the Fund for 1, 5, and 10 years and also compares the Fund’s performance with the average annual total returns of an index or other benchmark. Updated performance information is available by calling the Fund at 877-363-6333.

The Fund’s past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future.

Calendar Year Returns (before taxes)

The Fund’s calendar year-to-date return as of September 30, 2022 was (13.99)%. During the period shown in the bar chart, the best performance for a quarter was 16.98% (for the quarter ended June 30, 2020) and the worst performance was (24.44)% (for the quarter ended March 31, 2020).

Average Annual Total Returns (for Periods Ended December 31, 2021)

	1 Year	5 Years	10 Years
Return before taxes	31.81%	11.83%	11.52%
Return after taxes on distributions	28.22%	9.40%	8.80%
Return after taxes on distributions and sale of Fund shares	21.25%	8.97%	8.78%
S&P 500® Index (reflects no deductions for fees, expenses, or taxes)	28.71%	18.47%	16.55%

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, and the 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 (“IRAs”).