UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSRS

CERTIFIED SHAREHOLDER REPORT OF REGISTERED

MANAGEMENT INVESTMENT COMPANIES

INVESTMENT COMPANY ACT FILE NUMBER: 811-09237

EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER:	Calamos Advisors Trust
ADDRESS OF PRINCIPAL EXECUTIVE OFFICES:	2020 Calamos Court Naperville, Illinois 60563-2787
NAME AND ADDRESS OF AGENT FOR SERVICE:	John P. Calamos, Sr., Founder, Chairman and Global Chief Investment Officer Calamos Advisors LLC 2020 Calamos Court Naperville, Illinois 60563-2787

REGISTRANT’S TELEPHONE NUMBER, INCLUDING AREA CODE: (630) 245-7200

DATE OF FISCAL YEAR END: December 31, 2022

DATE OF REPORTING PERIOD: January 1, 2022 through June 30, 2022

ITEM 1. LETTER TO CONTRACT OWNERS.

Growth and Income Portfolio

SEMIANNUAL REPORT JUNE 30, 2022

Experience and Foresight

About Calamos Investments

For over 40 years, we have helped investors like you manage and build wealth to meet long-term objectives. Because investors have different time horizons, risk tolerances and goals, we offer investment portfolios to suit a variety of asset allocation needs. For example, our mutual funds include equity, fixed income and alternative funds. We offer US funds, as well as global and international choices.

We are dedicated to helping our clients build and protect wealth. We understand when you entrust us with your assets, you also entrust us with your achievements, goals and aspirations. We believe we best honor this trust by making investment decisions guided by integrity, by discipline and by our conscientious research.

We believe that an active, risk-conscious approach is essential for wealth creation. In the 1970s, we pioneered the use of convertible securities as a means to manage risk in volatile markets. We followed with strategies that combine convertibles and stocks, with the aim of participating in equity market upside with potentially less volatility than an all-stock portfolio. In the 1990s, we introduced our first stock fund, which invests in growth companies both large and small. Across our funds, our investment process seeks to manage risk at multiple levels and draws upon our experience investing through many market cycles. In a rapidly changing environment, we believe that this active management is essential.

We are global in our perspective. We believe globalization offers tremendous opportunities for countries and companies all over the world. In our US, global and international portfolios, we are seeking to capitalize on the potential growth of the global economy.

We believe there are opportunities in all markets. Our history traces back to the 1970s, a period of significant volatility and economic concerns. We have invested through multiple market cycles, each with its own challenges. Out of this experience comes our belief that the flipside of volatility is opportunity.

TABLE OF CONTENTS

Letter to Contract Owners	1
Investment Team Discussion	4
Expense Overview	8
Schedule of Investments	10
Statement of Assets and Liabilities	14
Statement of Operations	15
Statements of Changes In Net Assets	16
Notes to Financial Statements	17
Financial Highlights	24
Report of Independent Registered Public Accounting Firm	25
Trustee Approval of Management Agreement	26

Letter to Contract Owners

1

John P. calamos, sr.

Founder, Chairman
and Global Chief
Investment Officer

Dear Contract Holder:

Welcome to your semiannual report for the six months ended June 30, 2022. In this report, you will find commentary from the Calamos investment team as well as a listing of portfolio holdings, financial statements and highlights, and detailed information about the performance and positioning of Calamos Growth and Income Portfolio.

Before we explore the markets, economy, and the Portfolio in greater detail, all of us at Calamos Investments thank you for your continued trust in this challenging market environment. In this year’s newsfeeds, discouraging headlines often overshadowed more positive data, including strong corporate earnings, improving employment data, and consumer balance sheets.

In uncertain times, it is often easy to forget all the unprecedented hurdles that the economy has navigated. I began my investing career more than 50 years ago in the difficult financial markets of the 1970s, a period characterized by soaring inflation, rising interest rates, difficult conditions across asset classes, and geopolitical uncertainties—in other words, many problems similar to those that markets face today. Through the ensuing decades, I’ve seen there are long-term investment opportunities in all environments.

About the Portfolio

Calamos Growth and Income Portfolio follows a time-tested strategy to pursue consistent performance over full market cycles, as well as income. The Portfolio is managed to provide lower-volatility participation in the stock market, which we believe makes it a compelling choice for long-term asset allocation needs.

Our team can invest in an array of growth-and-income-producing investments, including stocks, convertible bonds, options, and traditional fixed income securities. As we have discussed in previous reports, this multi-asset class strategy is designed to enhance performance and mitigate exposure to downward moves in the stock market. Our broad opportunity set differentiates the Portfolio from “balanced” funds that focus more exclusively on stocks and traditional bonds and from equity funds that focus only on low stock prices or low volatility.

Letter to Contract Owners

2   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Review and Outlook

Surging volatility and rotations battered the markets during the semiannual period. Investors grappled with Russia’s invasion of Ukraine, inflation and supply chain disruptions, soaring energy prices, the start of a tightening cycle by a notably more hawkish Federal Reserve, rising interest rates, Covid-19 lockdowns in China, and mounting fears of a recession. Equity markets entered bear market territory, bond markets floundered, the 10-year US Treasury yield spiked, and credit spreads widened. Convertible securities, which blend attributes of equities and fixed income securities, also declined. As emotions ran high, even fundamentally strong companies experienced sharp sell-offs.

As we will discuss in this report, the Portfolio was not immune to the turbulence that roiled the capital markets. The Portfolio declined -19.83% for the reporting period, in line with the S&P 500 Index (-19.96%), slightly ahead of the ICE BofA All US Convertibles Ex Mandatory Index (-20.80%), and behind the Bloomberg US Aggregate Bond Index (-10.35%).

We maintain high conviction in our approach, based on our experience investing through many other market cycles, including difficult periods such as the Great Financial Crisis of 2008 and the Covid pandemic drawdown. We believe the Portfolio’s multi-asset class approach will serve contract holders well in the future as it has over longer periods, and we believe our broad investment universe will continue to provide our team with many advantages in managing risk and return. For example, convertible securities have tended to outperform traditional fixed income securities in rising rate environments, and they currently offer more attractive duration characteristics as well.

Our portfolio management team believes income-generating investments can enhance the overall risk/reward profile of the Portfolio. During the reporting period, income remained more difficult to come by. Although the Federal Reserve began raising short-term interest rates, and the 10-year US Treasury yield nearly doubled between the start and end of the reporting period, those increases were off low baselines. Additionally, many central banks around the world have maintained accommodative monetary policies to help promote economic activity. Against that backdrop, the Portfolio’s income distributions during the reporting period represent approximately 0.52% of its net asset value on January 1, 2022 (the beginning of the reporting period) on an annualized basis.

These next months will continue to test the investors’ resolve. We are prepared for persistent market volatility and saw-toothed market performance that may include additional sell-offs. Moreover, as midterm elections in the US approach, we expect the uncertain fiscal policy backdrop will add to market participants’ already

Letter to Contract Owners

3

heightened apprehension. We are likely to see sentiment-driven market behavior, in which even strong companies with good potential will also face pressure. Nevertheless, as we will discuss, our team remains confident in the longer-term trajectory of the US economy and the equity market.

In closing, we thank you again for your trust, and we look forward to helping you achieve your financial goals in the years to come.

Sincerely,

John P. Calamos, Sr.
Founder, Chairman and Global Chief Investment Officer

Indices Performance Source: Morningstar

Unmanaged index returns assume reinvestment of any and all distributions and, unlike fund returns, do not reflect fees, expenses or sales charges. Investors cannot invest directly in an index. Returns are in US dollar terms. The S&P 500 Index is an unmanaged index generally considered representative of the US stock market. The Bloomberg US Aggregate Bond Index is considered generally representative of the investment-grade bond market. The ICE BofA All US Convertibles Ex Mandatory Index represents the US convertibles securities market excluding mandatory convertibles.

The information contained herein, while not guaranteed as to accuracy or completeness, has been obtained from sources we believe to be reliable. There are certain risks involved with investing in convertible securities in addition to market risk, such as call risk, dividend risk, liquidity risk and default risk, which should be carefully considered prior to investing. Opinions are as of the publication date, subject to change and may not come to pass.

This information is being provided for informational purposes only and should not be considered investment advice.

4   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Investment Team Discussion

CALAMOS GROWTH AND INCOME PORTFOLIO

INVESTMENT TEAM DISCUSSION

How has the Portfolio performed?

For the six-month period ended June 30, 2022 (“semiannual period”), the Calamos Growth and Income Portfolio (the “Portfolio”) declined -19.83, slightly ahead of the -19.96% return of the S&P 500 Index (the Portfolio’s benchmark) while outperforming the ICE BofA All US Convertibles ex Mandatory Index -20.80% return.

In this Portfolio, we own equities and equity-sensitive convertible bonds or income producing convertible preferred stocks that we believe are best positioned to take advantage of upward equity movements and potentially limit losses on the downside. The Portfolio’s risk-conscious positioning was beneficial over the semiannual period, modestly cushioning the Portfolio at the equity markets’ series of lows. However, as stocks and bonds each turned in one of the worst starts to a calendar year ever, there was not much that worked well in capital markets. Nonetheless, the Portfolio’s sector positioning and security selection were each slightly additive to relative performance compared with the all-equity index.

We manage this Portfolio with the goal of achieving upside equity participation and potential downside resilience over full market cycles via a quality-growth strategy. Since its inception on May 19, 1999, the Portfolio has returned 7.47% on an annualized basis versus a 6.73% annualized gain for the S&P 500 Index and 7.88% annualized increase for the ICE BofA All US Convertibles ex Mandatory Index.

What is the Portfolio’s investment strategy?

The Portfolio invests primarily in a diversified portfolio of investments including stocks, convertible bonds, fixed income securities and options of US companies. In pursuing its total-return investment objective, the Portfolio’s investment team endeavors to use these different securities to strike the appropriate balance between risk and return with the intent of optimizing growth and income. As we focus on managing volatility, our goal for the Portfolio is to participate in a greater portion of equity market upside than downside over the long term.

Please discuss the Portfolio’s lower volatility characteristics.

We believe the Portfolio’s historically lower volatility characteristics are a byproduct of our investment style that focuses on participating in equity market upside with less volatility than the market as a whole. Beta is one popular statistic for measuring volatility. Beta considers a portfolio’s historic volatility versus the market, which is assigned a beta of 1.0. A portfolio with half the volatility of the market would have a beta of 0.5, while a portfolio with a beta of 2.0 would have been twice as volatile as the market.

Since its inception, the Portfolio has had a beta of 0.76 versus the S&P 500 Index. The Portfolio has therefore outperformed the broader equity market, as measured by the S&P 500 Index, with less volatility. Please note that past performance does not indicate future results and that beta is one of many measures of risk.

Although we compare our strategy to an all-equity benchmark, we typically invest a portion of the Portfolio in securities that exhibit less volatility, such as convertible securities. We believe this offers lower downside capture, which is a critical part of our risk-management process, but it can also cause Portfolio results to lag the benchmark return during periods of strong equity market performance.

SECTOR WEIGHTINGS

Information Technology	24.0%
Health Care	13.9
Consumer Discretionary	10.5
Financials	9.0
Industrials	8.9
Communication Services	8.8
Consumer Staples	5.8
Energy	5.3
Utilities	3.0
Materials	2.9
Real Estate	1.4
Other	0.2

Sector weightings are subject to change daily and are calculated as a percentage of net assets. The table excludes cash or cash equivalents, any government/sovereign bonds or broad based index hedging securities the Portfolio may hold.

5

Investment Team Discussion

What factors influenced performance?

In a wild first half of 2022, markets contended with a broad range of concerns, most notably a hawkish pivot from the Fed and Russia’s invasion of Ukraine. During the semiannual period, investors saw the 10-year Treasury yield climb nearly 200 basis points before retreating approximately 50 basis points as of period end. A dramatic spike in commodity prices corresponded with an increase in inflation expectations, gas prices weighed heavily on consumers, and a temporary inversion of the 2-year/10-year yield curve in April (an omen of possible recession) scared investors. While Covid moved to a lesser headline concern, re-openings as well as shutdowns weighed on investors’ assessments of economic potential as well as supply side inflation pressures. To be sure, some periods feel like much longer than six months. In light of a heavy dose of economic and financial concerns, the US equity market, as measured by the S&P 500 Index, was down -19.96% for the period, having pierced through bear market territory briefly in mid-June. From a fundamental standpoint, the S&P 500 saw positive earnings growth and no official drop in expectations, yet it was the change in multiples/sentiment that drove the market lower for the period. As of period end, the S&P 500 forward PE ratio had fallen below its trailing 25-year average.

Within the US equity market, as represented by the S&P 500 Index, value stocks outperformed growth stocks as investors became concerned about the valuations of longer-duration assets (growth stocks) and potential for a growth decline. Although neither performed well for the full semiannual period, S&P 500 Value fell -11.4%, while S&P 500 Growth declined -27.6%. Looking at sectors within the S&P 500 Index (-19.96%), energy (+32%) was the clear winner because of concerns around supply issues and the war in Ukraine. More defensive areas fared better with utilities (-1%), consumer staples (-6%), health care (-8%), industrials (-17%), materials (-18%), financials (-19%) all outperforming the market, while real estate (-20%), information technology (-27%), communication services (-30%), and consumer discretionary (-33%) lagged the index.

Growth and Income Portfolio versus the S&P 500 Index for six months ended 6/30/22

For the six-month period ended June 30, 2022, the Portfolio returned -19.83%, in line with the S&P 500 Index return of -19.96%.

Positive Influences on Performance

Industrials. The Portfolio’s favorable security selection and an overweight stance in industrials helped returns. In particular, our holdings in aerospace & defense and airlines were sources of strength.

Information Technology. An underweight stance and security selection in information technology added to the Portfolio’s performance. The main contributors within this sector were data processing & outsourced services and application software.

Negative Influences on Performance

Financials. Over the semiannual period, security selection within the financials sector hampered relative returns, as names in the multi-sector holdings and property & casualty insurance industries underperformed.

Utilities. Selection and an average underweight position in utilities weighed on results. Specifically, electric utilities and our lack of participation in gas utilities were detrimental.

Positioning and Portfolio Changes

In terms of economic sectors, information technology and health care represent the largest portfolio weights on an absolute basis. Conversely, materials and real estate comprise the smallest absolute sector weights with holdings. We maintain overweight allocations to industrials and energy versus the index. Aerospace & defense (within industrials) and oil & gas exploration & production (within energy) constitute the most significant relative overweights. We maintain underweight allocations to information technology and financials, with technology hardware, storage & peripherals (in information technology) and multi-sector holdings (in financials) among the underweight industries.

6   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Allocations to health care and energy rose during the period with increased weights in pharmaceuticals and oil & gas exploration & production. By contrast, allocations to information technology and consumer discretionary decreased over the period with reductions to semiconductors and home improvement retail.

How is the Portfolio positioned?

We believe the best positioning for this environment remains a defensive posture with a focus on lower-risk areas including lower-beta, high-quality balance sheets and higher return-on-capital businesses. Areas such as health care, staples, defense, software (cyber defense and system software) and parts of telecom provide some of those attributes. We have been positive on the supply/demand environment for energy, but we are turning somewhat cautious as global growth slows. From an asset class perspective, cash and short-term Treasuries are now a useful tool to use alongside equity and equity-sensitive securities to lower volatility in a multi-asset class portfolio given their now-positive yields. Despite elevated absolute volatility, we are selectively using options to gain some cyclical exposure in case our watch factors surprise to the upside.

What closing thoughts do you have for Portfolio shareholders?

In challenging economic and market environments, we believe balancing the long-term and short-term outlooks provides the best insights on portfolio positioning. Focusing on either one exclusively can lead to overly optimistic or pessimistic positioning that may not be warranted in the volatile markets.

Despite extreme circumstances over the past two years, we remain confident that the positive long-term growth trajectory of the US economy and the cash flow generation capabilities of US companies are intact. We see attractive long-term upside in the US equity market from current market levels, supported by current valuations that are generally between our long-term base and downside scenarios.

In the short term, the extreme conditions (both positive and negative) that occurred during these past two years have not yet reverted to a more normal environment or to the long-term mean. Since mid-2021, our expectation has been for a lower growth environment in 2022 and 2023. This slower growth outlook has been exacerbated by the war in Ukraine and China’s Covid shutdowns. These two factors have also worsened the inflation environment, causing most central banks around the world to raise interest rates, which should further slow growth. As we have seen in the semiannual period, slowing growth and rising inflation have led to significant declines in asset prices. We have yet to see significant reductions in earnings estimates, but we expect that to occur in the near term.

A mean reversion transition needs to occur for the challenging short-term environment to migrate to the more normalized long-term trend. We are watching several factors that would indicate this trend is occurring. These include improved labor market participation, a normalization of consumer spending versus income (including lower real goods consumption), lower retail inventory levels, improved supply chains for certain areas of the manufacturing sector, improved supply/demand for commodities (oil and food), central banks slowing their restrictive policies, resumption of China activity, and a reduction in military activity in Ukraine. This list is long and many of these factors may take considerable time to occur. However, the equity markets are forward looking, so improvement in any of these factors should be positive for asset markets.

7

Investment Team Discussion

ANNUALIZED RETURN: SINCE INCEPTION (5/19/99) THROUGH 6/30/22

GROWTH OF $10,000 FOR 10 YEAR PERIOD ENDED 6/30/22

AVERAGE ANNUAL TOTAL RETURN^† FOR THE PERIOD ENDED 6/30/22

1 YEAR	3 YEARS	5 YEARS	10 YEARS
-12.93%	8.91%	9.03%	8.65%

Performance data quoted represents past performance, which is no guarantee of future results. Current performance may be lower or higher than the performance quoted. The principal value and investment return of an investment will fluctuate so that your shares, when redeemed, may be worth more or less than their original cost. Returns are net of all fees and expenses incurred by the Portfolio. The graph and table do not reflect the deduction of taxes that a shareholder would pay on Portfolio distributions or the redemption of Portfolio shares. Performance figures of the Portfolio do not reflect fees charged pursuant to the terms of variable life insurance policies and variable annuity contracts. If these charges had been reflected, performance would have been lower.

†Average annual total return measures net investment income and capital gain or loss from portfolio investments as an annualized average, assuming reinvestment of income and capital gain distributions. Since inception data shown for ICE BofA All U.S. Convertibles Ex Mandatory Index is from 5/31/99 since data is only available for full monthly periods. Returns do not reflect sales charges, expenses and fees assessed in connection with the variable product. Sales charges, expenses and fees, which are determined by the variable product issuers, will vary and will lower the total return to the contract or policy owner.

The S&P 500 Index is an unmanaged index generally considered representative of the U.S. stock market.

The ICE BofA All U.S. Convertibles Ex Mandatory Index represents the U.S. convertibles securities market excluding mandatory convertibles. Source ICE Data Indices, LLC, used with permission. ICE permits use of the ICEBofA indices and related data on an ‘as is’ basis, makes no warranties regarding same, does not guarantee the suitability, quality, accuracy, timeliness, and/or completeness of the ICE BofA Indices or data included in, related to, or derived therefrom, assumes no liability in connection with the use of the foregoing and does not sponsor, endorse or recommend Calamos Advisors LLC or any of its products or services.

Index returns assume reinvestment of dividends and do not reflect deduction of fees and expenses. It is not possible to invest directly in an index.

The Fund’s use of derivative instruments involves investment risks and transaction costs to which the Fund would not be subject absent the use of these instruments and, accordingly, may result in losses greater than if they had not been used. Derivative instruments can be illiquid, may disproportionately increase losses and may have a potentially large impact on Fund performance.

This information is not intended to be a recommendation or investment advice, and does not constitute a solicitation to buy or sell securities. Certain statements in this commentary are forward-looking statements. Discussions of specific investments are for illustration only and are not intended as recommendations of individual investments. The forward looking statements and other views expressed herein are those of the portfolio managers as of the date of this report. Actual future results or occurrence may differ significantly from those anticipated in any forward-looking statements and the views expressed herein are subject to change at any time, due to numerous market and other factors. The Portfolio disclaims any obligation to update publicly or review any forward-looking statements or views expressed herein.

8   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Expense Overview

EXPENSE OVERVIEW

As a contract or policy owner, you incur certain costs. Because the Portfolio is a funding vehicle for annuities, policies and eligible plans, you may also incur sales charges and other fees related to your annuity, policy or eligible plan. In addition, the Portfolio incurs transaction costs and ongoing costs, including management fees, and other fund expenses, such as audit, legal and custodian fees.

The examples in this report are based on an investment of $1,000 made at the beginning of the period and held for the entire period from January 1, 2022 to June 30, 2022. It is intended to help you understand the ongoing costs associated with investing in the Portfolio and to compare these costs with the ongoing costs of investing in other mutual funds.

There are two parts to the examples table:

Actual

In this part of the table, you’ll see the actual expenses you would have paid on a $1,000 investment made at the beginning of the period and held for the entire period from January 1, 2022 to June 30, 2022, the period covered by this report. This table also shows the actual returns, after expenses, you would have earned during that time. This table can help you estimate your own expenses. For example, if you invested $8,600 in the Portfolio, simply divide $8,600 by $1,000, then multiply that result by the figure in the “Actual Expenses per $1,000” row. In this example, you would multiply 8.6 by the figure.

Hypothetical

In this part of the table, you’ll see the hypothetical expenses you would have paid on a $1,000 investment from January 1, 2022 to June 30, 2022, and the hypothetical returns, after expenses, you would have earned during that time. The Securities and Exchange Commission (SEC) has established the guidelines for this table, including the assumed 5% annual rate of return before expenses, which is what you’ll see in the table. Note that this table will not help you determine your own expenses, but will help you compare expenses of the Portfolio to the expenses of other mutual funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not include any transactional costs, such as sales charges (loads), redemption fees or exchange fees. Therefore, the second line of the table is useful in comparing ongoing costs only and will not help you determine the relative total costs of owning different funds. In addition, if these transactions costs were included, your costs would have been higher.

9

Expense Overview

The actual and hypothetical examples shown assume a $1,000 investment at the beginning of the period, January 1, 2022, and held through June 30, 2022.

Actual Expenses per $1,000*	$	5.85
Actual - Ending Balance	$	801.70
Hypothetical Expenses per $1,000*	$	6.56
Hypothetical - Ending Value	$	1,018.30
Annualized expense ratio		1.31	%

*Expenses are equal to the Portfolio’s annualized expense ratio multiplied by the average account value over the period, multiplied by 181/365.

10   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Schedule of Investments June 30, 2022 (Unaudited)

See accompanying Notes to Schedule of Investments

PRINCIPAL AMOUNT		VALUE
CONVERTIBLE BONDS (16.1%)
Communication Services (1.3%)
	Liberty Media Corp.
90,000	1.375%, 10/15/23	$106,248
31,000	0.500%, 12/01/50*		34,751
170,000	Live Nation Entertainment, Inc. 2.000%, 02/15/25		178,918
47,000	Twitter, Inc. 0.250%, 06/15/24		46,282
		366,199
Consumer Discretionary (3.2%)
125,000	Airbnb, Inc. 0.000%, 03/15/26		103,589
194,000	Booking Holdings, Inc.^ 0.750%, 05/01/25		230,790
50,000	DISH Network Corp. 0.000%, 12/15/25		35,202
235,000	Ford Motor Company 0.000%, 03/15/26		215,318
31,000	Liberty Broadband Corp.* 2.750%, 09/30/50		29,554
95,000	Marriott Vacations Worldwide Corp. 0.000%, 01/15/26		87,082
7,000	Tesla, Inc. 2.000%, 05/15/24		75,918
115,000	Vail Resorts, Inc.^ 0.000%, 01/01/26		100,487
		877,940
Energy (1.1%)
55,000	EQT Corp. 1.750%, 05/01/26		132,241
85,000	Pioneer Natural Resources Company 0.250%, 05/15/25		184,114
		316,355
Financials (0.2%)
50,000	Ares Capital Corp.^ 4.625%, 03/01/24	52,307
Health Care (3.0%)
60,000	Conmed Corp. 2.250%, 06/15/27		56,261
110,000	Dexcom, Inc. 0.250%, 11/15/25		101,131
52,000	Envista Holdings Corp. 2.375%, 06/01/25		99,588
44,000	Halozyme Therapeutics, Inc. 0.250%, 03/01/27		38,898
46,000	Integra LifeSciences Holdings Corp. 0.500%, 08/15/25		43,335
200,000	Jazz Investments I, Ltd. 2.000%, 06/15/26		235,248

PRINCIPAL AMOUNT		VALUE
70,000	Omnicell, Inc. 0.250%, 09/15/25	$89,272
95,000	Pacira BioSciences, Inc. 0.750%, 08/01/25		98,999
55,000	Tandem Diabetes Care, Inc.*^ 1.500%, 05/01/25		51,340
		814,072
Industrials (3.2%)
55,000	Air Transport Services Group, Inc. 1.125%, 10/15/24		59,529
17,000	Chart Industries, Inc.*^ 1.000%, 11/15/24		49,213
170,000	John Bean Technologies Corp. 0.250%, 05/15/26		158,047
115,000	Middleby Corp. 1.000%, 09/01/25		130,249
275,000	Southwest Airlines Company 1.250%, 05/01/25		325,639
185,000	Uber Technologies, Inc. 0.000%, 12/15/25		148,093
		870,770
Information Technology (3.5%)
41,000	Akamai Technologies, Inc. 0.375%, 09/01/27		40,761
78,000	Bill.com Holdings, Inc.* 0.000%, 04/01/27		60,783
39,000	CyberArk Software, Ltd.^ 0.000%, 11/15/24		41,160
28,000	Datadog, Inc. 0.125%, 06/15/25		35,671
	Enphase Energy, Inc.
65,000	0.000%, 03/01/26		64,024
65,000	0.000%, 03/01/28		64,547
150,000	Microchip Technology, Inc.^ 0.125%, 11/15/24		150,205
30,000	Nova, Ltd. 0.000%, 10/15/25		38,733
155,000	ON Semiconductor Corp. 0.000%, 05/01/27		178,819
50,000	Palo Alto Networks, Inc. 0.375%, 06/01/25		85,803
55,000	Perficient, Inc.* 0.125%, 11/15/26		44,815
47,000	Silicon Laboratories, Inc. 0.625%, 06/15/25		60,959
60,000	Tyler Technologies, Inc. 0.250%, 03/15/26		56,701
30,000	Workday, Inc. 0.250%, 10/01/22		31,394
		954,375

11

Schedule of Investments June 30, 2022 (Unaudited)

See accompanying Notes to Schedule of Investments

PRINCIPAL AMOUNT		VALUE
Materials (0.2%)
35,000	Lithium Americas Corp.* 1.750%, 01/15/27	$29,368
33,000	MP Materials Corp.* 0.250%, 04/01/26		32,374
		61,742
Real Estate (0.4%)
115,000	Pebblebrook Hotel Trust 1.750%, 12/15/26	104,573
	TOTAL CONVERTIBLE BONDS (Cost $4,278,443)	4,418,333

NUMBER OF SHARES			VALUE
CONVERTIBLE PREFERRED STOCKS (7.0%)
Communication Services (1.3%)
300		2020 Cash Mandatory Exchangeable Trust* 5.250%, 06/01/23	345,188
Consumer Discretionary (0.6%)
1,495		Aptiv, PLC 5.500%, 06/15/23	157,558
Financials (0.6%)
1,180		AMG Capital Trust II^ 5.150%, 10/15/37		60,427
1,905		KKR & Company, Inc.^ 6.000%, 09/15/23		111,385
			171,812
Health Care (0.6%)
1,750		Boston Scientific Corp. 5.500%, 06/01/23	177,520
Information Technology (0.9%)
170		Broadcom, Inc. 8.000%, 09/30/22	255,536
Utilities (3.0%)
1,700		AES Corp. 6.875%, 02/15/24		146,761
4,780		American Electric Power Company, Inc.^ 6.125%, 08/15/23		258,120
875		CenterPoint Energy, Inc. (Warner Media, LLC, Charter Communications Time, Inc.)§** 4.566%, 09/15/29		41,301
4,430		DTE Energy Company 6.250%, 11/01/22		227,791
		NextEra Energy, Inc.
1,390		4.872%, 09/01/22		78,271
1,210		6.219%, 09/01/23		59,471
			811,715
	TOTAL CONVERTIBLE PREFERRED STOCKS (Cost $1,816,918)		1,919,329

NUMBER OF SHARES		VALUE
Common Stocks (70.3%)
Communication Services (6.2%)
490	Alphabet, Inc. - Class A#~	$1,067,837
3,690	Comcast Corp. - Class A		144,796
1,695	Meta Platforms, Inc. - Class A#		273,319
375	Netflix, Inc.#		65,576
1,615	Walt Disney Company#		152,456
		1,703,984
Consumer Discretionary (6.6%)
6,900	Amazon.com, Inc.#~		732,849
23	Booking Holdings, Inc.#		40,227
560	Home Depot, Inc.		153,591
410	Lowe’s Companies, Inc.		71,615
560	McDonald’s Corp.		138,253
2,805	MGM Resorts International		81,205
1,340	NIKE, Inc. - Class B		136,948
895	Starbucks Corp.		68,369
385	Tesla, Inc.#		259,266
655	TJX Companies, Inc.		36,582
270	Ulta Beauty, Inc.#		104,079
		1,822,984
Consumer Staples (5.8%)
4,990	Coca-Cola Company		313,921
325	Costco Wholesale Corp.		155,766
350	Estee Lauder Companies Inc. - Class A		89,135
2,930	Mondelez International, Inc. - Class A		181,924
1,240	PepsiCo, Inc.		206,658
2,050	Philip Morris International, Inc.		202,417
1,910	Procter & Gamble Company		274,639
1,340	Walmart, Inc.		162,917
		1,587,377
Energy (4.2%)
1,770	Chevron Corp.		256,260
1,675	ConocoPhillips		150,432
3,480	Exxon Mobil Corp.		298,027
940	Hess Corp.		99,584
1,505	Marathon Petroleum Corp.		123,726
1,730	Schlumberger, NV		61,865
1,875	Sysco Corp.		158,831
		1,148,725
Financials (8.2%)
485	American Express Company		67,231
1,350	American International Group, Inc.		69,025
583	Assurant, Inc.		100,772
5,935	Bank of America Corp.		184,757
125	BlackRock, Inc.		76,130
2,330	Charles Schwab Corp.		147,209

12   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Schedule of Investments June 30, 2022 (Unaudited)

See accompanying Notes to Schedule of Investments

NUMBER OF SHARES		VALUE
1,370	Citigroup, Inc.	$63,006
1,140	Discover Financial Services		107,821
270	Goldman Sachs Group, Inc.		80,195
4,520	Huntington Bancshares, Inc.		54,376
2,540	JPMorgan Chase & Company		286,029
6,675	KeyCorp		115,010
1,020	Linde, PLC		200,512
1,555	Marsh & McLennan Companies, Inc.		241,414
3,105	Morgan Stanley		236,166
510	Northern Trust Corp.		49,205
4,100	Wells Fargo & Company		160,597
		2,239,455
Health Care (10.3%)
2,020	Abbott Laboratories		219,473
1,985	AbbVie, Inc.		304,023
1,210	Alcon, Inc.		84,567
375	Anthem, Inc.		180,968
2,522	Avantor Funding, Inc#		78,434
2,585	Bristol-Myers Squibb Company		199,045
699	Danaher Corp.		177,211
480	Eli Lilly & Company		155,630
255	Intuitive Surgical, Inc.#		51,181
2,465	Johnson & Johnson		437,562
4,205	Pfizer, Inc.		220,468
230	Thermo Fisher Scientific, Inc.~		124,954
1,160	UnitedHealth Group, Inc.		595,811
		2,829,327
Industrials (5.7%)
10,170	CSX Corp.		295,540
1,455	Honeywell International, Inc.		252,894
1,085	JB Hunt Transport Services, Inc.		170,855
540	Northrop Grumman Corp.		258,428
4,280	Raytheon Technologies Corp.		411,351
230	Stryker Corp.		45,754
580	Union Pacific Corp.		123,702
		1,558,524
Information Technology (19.6%)
765	Accenture, PLC - Class A		212,402
225	Adobe, Inc.#~		82,364
505	Advanced Micro Devices, Inc.#		38,617
12,215	Apple, Inc.~		1,670,035
2,510	Cisco Systems, Inc.		107,026
1,240	Fidelity National Information Services, Inc.		113,671
100	Intuit, Inc.		38,544
345	Lam Research Corp.		147,022
795	Mastercard, Inc. - Class A		250,807

NUMBER OF SHARES			VALUE
1,005		Micron Technology, Inc.	$55,556
6,100		Microsoft Corp.~		1,566,663
2,000		NVIDIA Corp.		303,180
805		Oracle Corp.		56,245
565		QUALCOMM, Inc.		72,173
830		Salesforce.com, Inc.#		136,983
250		ServiceNow, Inc.#~		118,880
2,130		Visa, Inc. - Class A		419,376
			5,389,544
Materials (2.7%)
885		Celanese Corp.		104,085
1,195		Eaton Corp., PLC		107,251
4,620		Freeport-McMoRan, Inc.		135,181
1,140		Linde, PLC		327,784
495		PPG Industries, Inc.		56,599
			730,900
Real Estate (1.0%)
680		American Tower Corp.		173,801
3,081		Invitation Homes, Inc.		109,622
			283,423
	Total Common Stocks (Cost $11,657,243)		19,294,243

PRINCIPAL AMOUNT			VALUE
U.S. Government And Agency Securities (2.1%)
		U.S. Treasury Note
295,000		2.500%, 05/31/24^		292,396
295,000		2.250%, 03/31/24	291,318
	Total U.S. Government And Agency Securities (Cost $588,722)		583,714

NUMBER OF CONTRACTS/ NOTIONAL AMOUNT		VALUE
PURCHASED OPTIONS (0.3%) #
Consumer Discretionary (0.1%)
27 286,767	Amazon.com, Inc. Put, 09/16/22, Strike $100.00		17,415
2 216,908	Tesla, Inc. Call, 09/16/22, Strike $950.00	2,925
		20,340
Financials (0.0%)
	Berkshire Hathaway, Inc.
13 354,926	Call, 11/18/22, Strike $310.00		5,135
10 273,020	Call, 09/16/22, Strike $340.00	175
		5,310

13

Schedule of Investments June 30, 2022 (Unaudited)

See accompanying Notes to Schedule of Investments

NUMBER OF CONTRACTS/ NOTIONAL AMOUNT		VALUE
Other (0.2%)
125 23,078,500	iShares MSCI EAFE ETF Call, 09/16/22, Strike $71.00	$3,000
125 23,078,500	iShares MSCI EAFE ETF Call, 09/16/22, Strike $78.00		2,625
16 2,732,784	iShares Russell 2000 ETF Call, 12/16/22, Strike $180.00		12,888
38 6,490,362	iShares Russell 2000 ETF Call, 09/16/22, Strike $200.00		2,375
1 378,538	S&P 500 Index Put, 09/16/22, Strike $4,000.00		28,555
		49,443
	Total PURCHASED OPTIONS (Cost $208,917)	75,093

NUMBER OF SHARES/ PRINCIPAL AMOUNT			VALUE
INVESTMENT OF CASH COLLATERAL FOR SECURITIES LOANED (5.0%)
1,366,030		State Street Navigator Securities Lending Government Money Market Portfolio, 1.530%†*** (Cost $1,366,030)	1,366,030
	TOTAL INVESTMENTS (100.8%) (Cost $19,916,273)		27,656,742
PAYABLE UPON RETURN OF SECURITIES ON LOAN (-5.0%)			(1,366,030)
OTHER ASSETS, LESS LIABILITIES (4.2%)			1,157,827
NET ASSETS (100.0%)			$27,448,539

NUMBER OF CONTRACTS/ NOTIONAL AMOUNT			VALUE
WRITTEN OPTION (0.0%) #
Consumer Discretionary (0.0%)
27 286,767	Amazon.com, Inc. Put, 09/16/22, Strike $80.00 (Premium $7,073)	$(4,482)

NOTES TO SCHEDULE OF INVESTMENTS

*Securities issued and sold pursuant to a Rule 144A transaction are exempted from the registration requirement of the Securities Act of 1933, as amended. These securities may only be sold to qualified institutional buyers (“QIBs”), such as the Fund. Any resale of these securities must generally be effected through a sale that is registered under the Act or otherwise exempted from such registration requirements.

^Security, or portion of security, is on loan.

§Securities exchangeable or convertible into securities of one or more entities that are different than the issuer. Each entity is identified in the parenthetical.

**Step coupon security. Coupon changes periodically based upon a predetermined schedule. The rate shown is the rate in effect at June 30, 2022.

#Non-income producing security.

~Security, or portion of security, is segregated as collateral (or collateral for potential future transactions) for written options. The aggregate value of such securities is $192,838.

†Represents investment of cash collateral received from securities on loan as of June 30, 2022.

***The rate disclosed is the 7 day net yield as of June 30, 2022.

Note: The date on options represents the expiration date of the option contract. The option contract may be exercised at any date on or before the date shown.

14   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Statement of Assets and Liabilities June 30, 2022 (Unaudited)

See accompanying Notes to Financial Statements

ASSETS
Investments in securities, at value (cost $19,916,273)				$	27,656,742
Cash with custodian					1,170,203
Receivables:
	Accrued interest and dividends				23,964
	Investments sold				61,906
	Portfolio shares sold				6,113
Prepaid expenses					1,511
Other assets					70,652
			Total assets		28,991,091
LIABILITIES
Collateral for securities loaned					1,366,030
Options written, at value (premium $7,073)					4,482
Payables:
	Portfolio shares redeemed				29,250
	Affiliates:
		Investment advisory fees			17,587
		Deferred compensation to trustees			70,652
		Trustees’ fees and officer compensation			677
	Other accounts payable and accrued liabilities				53,874
			Total liabilities		1,542,552
			NET ASSETS	$	27,448,539
COMPOSITION OF NET ASSETS
Paid in capital				$	19,532,868
Accumulated distributable earnings (loss)					7,915,671
			NET ASSETS	$	27,448,539
Shares outstanding (no par value; unlimited number of shares authorized)					1,637,542
Net asset value and redemption price per share				$	16.76

See accompanying Notes to Financial Statements

Statement of Operations Six Months Ended June 30, 2022 (Unaudited)

15

INVESTMENT INCOME
Interest			$	19,438
(Amortization)/accretion of investment securities				(52,310	)
	Net interest			(30,840	)
Dividends				213,738
Dividend taxes withheld				(100	)
Securities lending income				2,032
		Total investment income		182,798
EXPENSES
Investment advisory fees				117,439
Legal fees				29,633
Audit fees				22,226
Printing and mailing fees				11,292
Trustees’ fees and officer compensation				7,269
Accounting fees				6,312
Transfer agent fees				4,232
Custodian fees				2,468
Fund administration fees				944
Other				4,019
		Total expenses		205,834
		NET INVESTMENT INCOME (LOSS)		(23,036	)
REALIZED AND UNREALIZED GAIN (LOSS)
Net realized gain (loss) from:
	Investments, excluding purchased options			755,084
	Purchased options			(68,749	)
	Forward foreign currency contracts			7,483
	Written options			6,868
Change in net unrealized appreciation/(depreciation) on:
	Investments, excluding purchased options			(7,507,434	)
	Purchased options			(115,085	)
	Forward foreign currency contracts			(2,326	)
	Written options			531
		NET GAIN (LOSS)		(6,923,628	)
		NET INCREASE (DECREASE) IN NET ASSETS RESULTING FROM OPERATIONS	$	(6,946,664	)

16   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

See accompanying Notes to Financial Statements

Statements of Changes in Net Assets

		(Unaudited) Six Months Ended June 30, 2022			Year Ended December 31, 2021
OPERATIONS
Net investment income (loss)		$	(23,036	)	$	(137,234	)
Net realized gain (loss)			700,686			2,511,603
Change in unrealized appreciation/(depreciation)			(7,624,314	)		4,233,097
Net increase (decrease) in net assets resulting from operations			(6,946,664	)		6,607,466
DISTRIBUTIONS TO SHAREHOLDERS
Total distributions			(2,644,199	)		(2,796,715	)
CAPITAL SHARE TRANSACTIONS
	Issued		940,276			1,942,538
	Issued in reinvestment of distributions		2,644,199			2,796,715
	Redeemed		(2,207,731	)		(5,141,012	)
Net increase (decrease) in net assets from capital share transactions			1,376,744			(401,759	)
TOTAL INCREASE (DECREASE) IN NET ASSETS			(8,214,119	)		3,408,992
NET ASSETS
Beginning of period		$	35,662,658		$	32,253,666
End of period		$	27,448,539		$	35,662,658
CAPITAL SHARE TRANSACTIONS
Shares issued			47,913			91,568
Shares issued in reinvestment of distributions			141,661			141,899
Shares redeemed			(112,842	)		(240,628	)
Net increase (decrease) in capital shares outstanding			76,732			(7,161	)

17

Notes to Financial Statements (Unaudited)

Note 1 – Organization and Significant Accounting Policies

Organization. CALAMOS ADVISORS TRUST (the “Trust”), a Massachusetts business trust organized February 17, 1999, consists of a single series, Calamos Growth and Income Portfolio (the “Portfolio”), which commenced operations on May 19, 1999.

The Trust currently offers the Portfolio’s shares to certain life insurance companies for allocation to certain separate accounts established for the purpose of funding qualified and non-qualified variable annuity contracts and variable life insurance contracts. The Portfolio seeks high long-term total return through growth and current income.

The Portfolio invests primarily in a diversified portfolio of convertible instruments (including synthetic convertible instruments), equity and fixed-income securities of U.S. companies without regard to market capitalization. In pursuing its investment objective, the Portfolio attempts to utilize these different types of securities to strike, in the investment adviser’s opinion, the appropriate balance between risk and return in terms of growth and income.

Significant Accounting Policies. The financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (U.S. GAAP), and the Portfolio is considered an investment company under U.S. GAAP and follows the accounting and reporting guidance applicable to investment companies. The Portfolio adheres to the accounting and reporting requirements set forth in ASU 2013-08 and ASC 946. Under U.S. GAAP, management is required to make certain estimates and assumptions at the date of the financial statements and actual results may differ from those estimates. Subsequent events, if any, through the date that the financial statements were issued, have been evaluated in the preparation of the financial statements. The following summarizes the significant accounting policies of the Portfolio:

Portfolio Valuation. The valuation of the Portfolio’s investments is in accordance with policies and procedures adopted by and under the ultimate supervision of the board of trustees.

Portfolio securities that are traded on U.S. securities exchanges, except option securities, are valued at the official closing price, which is the last current reported sales price on its principal exchange at the time the Portfolio determines its net asset value (“NAV”). Securities traded in the over-the-counter market and quoted on The NASDAQ Stock Market are valued at the NASDAQ Official Closing Price, as determined by NASDAQ, or lacking a NASDAQ Official Closing Price, the last current reported sale price on NASDAQ at the time a Portfolio determines its NAV. When a last sale or closing price is not available, equity securities, other than option securities, that are traded on a U.S. securities exchange and other equity securities traded in the over-the-counter market are valued at the mean between the most recent bid and asked quotations on its principal exchange in accordance with guidelines adopted by the board of trustees. Each option security traded on a U.S. securities exchange is valued at the mid-point of the consolidated bid/ask quote for the option security, also in accordance with guidelines adopted by the board of trustees. Each over-the-counter option that is not traded through the Options Clearing Corporation is valued either by an independent pricing agent approved by the board of trustees or based on a quotation provided by the counterparty to such option under the ultimate supervision of the board of trustees.

Fixed income securities, certain convertible preferred securities, and non-exchange traded derivatives are normally valued by independent pricing services or by dealers or brokers who make markets in such securities. Valuations of such fixed income securities, certain convertible preferred securities, and non-exchange traded derivatives consider yield or price of equivalent securities of comparable quality, coupon rate, maturity, type of issue, trading characteristics and other market data and do not rely exclusively upon exchange or over-the-counter prices.

Trading on European and Far Eastern exchanges and over-the-counter markets is typically completed at various times before the close of business on each day on which the New York Stock Exchange (“NYSE”) is open. Each security trading on these exchanges or in over-the-counter markets may be valued utilizing a systematic fair valuation model provided by an independent pricing service approved by the board of trustees. The valuation of each security that meets certain criteria in relation to the valuation model is systematically adjusted to reflect the impact of movement in the U.S. market after the foreign markets close. Securities that do not meet the criteria, or that are principally traded in other foreign markets, are valued as of the last reported sale price at the time the Portfolio determines its NAV, or when reliable market prices or quotations are not readily available, at the mean between the most recent bid and asked quotations as of the close of the appropriate exchange or other designated time. Trading of foreign securities may not take place on every NYSE business day. In addition, trading may take place in various foreign markets on Saturdays or on other days when the NYSE is not open and on which the Portfolio’s NAV is not calculated.

18   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Notes to Financial Statements (Unaudited)

If the pricing committee determines that the valuation of a security in accordance with the methods described above is not reflective of a fair value for such security, the security is valued at a fair value by the pricing committee, under the ultimate supervision of the board of trustees, following the guidelines and/or procedures adopted by the board of trustees.

The Portfolio also may use fair value pricing, pursuant to guidelines adopted by the board of trustees and under the ultimate supervision of the board of trustees, if trading in the security is halted or if the value of a security it holds is materially affected by events occurring before the Portfolio’s pricing time but after the close of the primary market or exchange on which the security is listed. Those procedures may utilize valuations furnished by pricing services approved by the board of trustees, which may be based on market transactions for comparable securities and various relationships between securities that are generally recognized by institutional traders, a computerized matrix system, or appraisals derived from information concerning the securities or similar securities received from recognized dealers in those securities.

When fair value pricing of securities is employed, the prices of securities used by a Portfolio to calculate its NAV may differ from market quotations or official closing prices. In light of the judgment involved in fair valuations, there can be no assurance that a fair value assigned to a particular security is accurate.

Investment Transactions. Investment transactions are recorded on a trade date basis as of June 30, 2022. Net realized gains and losses from investment transactions are reported on an identified cost basis. Interest income is recognized using the accrual method and includes accretion of original issue and market discount and amortization of premium. Dividend income is recognized on the ex-dividend date, except that certain dividends from foreign securities are recorded as soon as the information becomes available after the ex-dividend date.

Foreign Currency Translation. Values of investments and other assets and liabilities denominated in foreign currencies are translated into U.S. dollars using a rate quoted by a major bank or dealer in the particular currency market, as reported by a recognized quotation dissemination service.

The Portfolio does not isolate that portion of the results of operations resulting from changes in foreign exchange rates on investments from the fluctuations arising from changes in market prices of securities held. Such fluctuations are included with the net realized and unrealized gain or loss from investments.

Reported net realized foreign currency gains or losses arise from disposition of foreign currency, the difference in the foreign exchange rates between the trade and settlement dates on securities transactions, and the difference between the amounts of dividends, interest and foreign withholding taxes recorded on the ex-date or accrual date and the U.S. dollar equivalent of the amounts actually received or paid. Net unrealized foreign exchange gains and losses arise from changes (due to the changes in the exchange rate) in the value of foreign currency and other assets and liabilities denominated in foreign currencies held at period end.

Allocation of Expenses Among Funds. Expenses directly attributable to the Portfolio are charged to the Portfolio; certain other common expenses of Calamos Advisors Trust, Calamos Investment Trust, Calamos Convertible Opportunities and Income Fund, Calamos Convertible and High Income Fund, Calamos Strategic Total Return Fund, Calamos Global Total Return Fund, Calamos Global Dynamic Income Fund, Calamos Dynamic Convertible and Income Fund, and Calamos Long/Short Equity & Dynamic Income Trust are allocated proportionately among each Fund to which the expenses relate in relation to the net assets of each Fund or on another reasonable basis.

Income Taxes. No provision has been made for U.S. income taxes because the Trust’s policy is to continue to qualify as a regulated investment company under the Internal Revenue Code of 1986, as amended, and distribute to shareholders substantially all of the Portfolio’s taxable income and net realized gains.

Dividends and distributions paid to shareholders are recorded on the ex-dividend date. The amount of dividends and distributions from net investment income and net realized capital gains is determined in accordance with federal income tax regulations, which may differ from U.S. generally accepted accounting principles. To the extent these “book/tax” differences are permanent in nature, such amounts are reclassified within the capital accounts based on their federal tax-basis treatment. These differences are primarily due to differing treatments for foreign currency transactions, contingent payment debt instruments and methods of amortizing and accreting for fixed income securities. The financial statements are not adjusted for temporary differences.

19

Notes to Financial Statements (Unaudited)

The Portfolio recognized no liability for uncertain tax positions. A reconciliation is not provided as the beginning and ending amounts of unrecognized benefits are zero, with no interim additions, reductions or settlements. Tax years 2018 - 2021 remain subject to examination by the U.S. and the State of Illinois tax jurisdictions.

Indemnifications. Under the Trust’s organizational documents, the Trust is obligated to indemnify its officers and trustees against certain liabilities incurred by them by reason of having been an officer or trustee of the Trust. In addition, in the normal course of business, the Trust may enter into contracts that provide general indemnifications to other parties. The Portfolio’s maximum exposure under these arrangements is unknown as this would involve future claims that may be made against the Portfolio that have not yet occurred. Currently, the Portfolio’s management expects the risk of material loss in connection to a potential claim to be remote.

Note 2 – Investment Adviser and Transactions With Affiliates Or Certain Other Parties

Pursuant to an investment advisory agreement with Calamos Advisors LLC (“Calamos Advisors”), the Portfolio pays a monthly investment advisory fee based on the average daily net assets of the Portfolio at the annual rate of 0.75%.

The Portfolio reimburses Calamos Advisors for a portion of compensation paid to the Trust’s Chief Compliance Officer. This compensation is reported as part of the “Trustees’ fees and officer compensation” expense on the Statement of Operations.

A trustee and certain officers of the Trust are also officers and directors of CFS and Calamos Advisors. Such trustee and officers serve without direct compensation from the Trust. The Trust’s Statement of Additional Information contains additional information about the Trust’s Trustees and Officers and is available without charge, upon request, at www.calamos.com or by calling 800.582.6959.

The Trust has adopted a deferred compensation plan (the “Plan”). Under the Plan, a trustee who is not an “interested person” (as defined in the 1940 Act) and has elected to participate in the Plan (a “participating trustee”) may defer receipt of all or a portion of their compensation from the Trust. The deferred compensation payable to the participating trustee is credited to the trustee’s deferral account as of the business day such compensation would have been paid to the participating trustee. The value of amounts deferred for a participating trustee is determined by reference to the change in value of Class I shares of one or more funds of Calamos Investment Trust designated by the participant. The value of the account increases with contributions to the account or with increases in the value of the measuring shares, and the value of the account decreases with withdrawals from the account or with declines in the value of the measuring shares. Deferred compensation of $70,652 is included in “Other assets” on the Statement of Assets and Liabilities at June 30, 2022. The Portfolio’s obligation to make payments under the Plan is a general obligation of the Portfolio and is included in “Payable for deferred compensation to trustees” on the Statement of Assets and Liabilities at June 30, 2022.

Note 3 – Investments

The cost of purchases and proceeds from sales of long-term investments for the period ended June 30, 2022 were as follows:

	U.S. Government Securities	Other
Cost of purchases	$588,608	$2,887,107
Proceeds from sales	—	5,675,837

The cost basis of investments for federal income tax purposes at June 30, 2022 was as follows*:

Cost basis of investments	$19,909,200
Gross unrealized appreciation	8,587,544
Gross unrealized depreciation	(844,484	)
Net unrealized appreciation (depreciation)	$7,743,060

*Because tax adjustments are calculated annually, the above table does not reflect tax adjustments. For the previous fiscal year’s federal income tax information, please refer to the Notes to Financial Statements section in the Portfolio’s most recent annual report.

20   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Notes to Financial Statements (Unaudited)

Note 4 – Income Taxes

The tax character of distributions for the period ended June 30, 2022 will be determined at the end of the Portfolio’s current fiscal year.

Distributions for the year ended December 31, 2021 were characterized for federal income tax purposes as follows:

	YEAR ENDED DECEMBER 31, 2021
Distributions paid from:
Ordinary income	$735,220
Long-term capital gains	2,061,495
Return of capital	—

As of December 31, 2021, the components of accumulated earnings/(loss) on a tax basis were as follows:

Undistributed ordinary income	$434,005
Undistributed capital gains	2,165,404
Total undistributed earnings	2,599,409
Accumulated capital and other losses	(61,129	)
Net unrealized gains/(losses)	15,091,845
Total accumulated earnings/(losses)	17,630,125
Other	(123,591	)
Paid-in-capital	18,156,124
Net assets applicable to common shareholders	$35,662,658

Note 5 – Derivative Instruments

Foreign Currency Risk. The Portfolio may engage in portfolio hedging with respect to changes in currency exchange rates by entering into forward foreign currency contracts to purchase or sell currencies. A forward foreign currency contract is a commitment to purchase or sell a foreign currency at a future date at a negotiated forward rate. Risks associated with such contracts include, among other things, movement in the value of the foreign currency relative to the U.S. dollar and the ability of the counterparty to perform.

To mitigate the counterparty risk, the Portfolio may enter into an International Swaps and Derivatives Association, Inc. Master Agreement (“ISDA Master Agreement”) or similar agreement with its derivative contract counterparties. An ISDA Master Agreement is a bilateral agreement between the Portfolio and a counterparty that governs Over-The-Counter derivatives and foreign exchange contracts and typically contains, among other things, collateral posting terms and netting provisions in the event of a default and/or termination event. Under an ISDA Master Agreement, the Portfolio may, under certain circumstances, offset with the counterparty certain derivative financial instrument’s payables and/or receivables with collateral held and/or posted and create one single net payment. The provisions of the ISDA Master Agreement typically permit a single net payment in the event of default (close-out netting) including the bankruptcy or insolvency of the counterparty. Generally, collateral is exchanged between the Portfolio and the counterparty and the amount of collateral due from the Portfolio or to a counterparty has to exceed a minimum transfer amount threshold before a transfer has to be made. To the extent amounts due to the Portfolio from its counterparties are not fully collateralized, contractually or otherwise, the Portfolio bears the risk of loss from counterparty nonperformance. When a Portfolio is required to post collateral under the terms of a derivatives transaction and master netting agreement, the Portfolio’s custodian holds the collateral in a segregated account, subject to the terms of a tri-party agreement among the Portfolio, the custodian and the counterparty. The master netting agreement and tri-party agreement provide, in relevant part, that the counterparty may have rights to the amounts in the segregated account in the event that the Portfolio defaults in its obligation with respect to the derivative instrument that is subject to the collateral requirement.  When a counterparty is required to post collateral under the terms of a derivatives transaction and master netting agreement, the counterparty delivers such amount to the Portfolio’s custodian.  The master netting agreement provides, in relevant part, that the Portfolio may have rights to such collateral in the event that the counterparty defaults in its obligation with respect to the derivative instrument that is subject to the collateral requirement.

21

Notes to Financial Statements (Unaudited)

For financial reporting purposes, the Portfolio does not offset derivative assets and derivative liabilities that are subject to netting arrangements in the Statement of Assets and Liabilities. The Portfolio’s net counterparty exposure is reflected in the counterparty table below. The net unrealized gain, if any, represents the credit risk to the Portfolio on a forward foreign currency contract. The contracts are valued daily at forward foreign exchange rates. The Portfolio realizes a gain or loss when a position is closed or upon settlement of the contracts. Please see the disclosure regarding ISDA Master Agreements under Foreign Currency Risk within this note.

As of June 30, 2022, the Portfolio does not have outstanding forward foreign currency contracts on the Schedule of Investments.

Equity Risk. The Portfolio may engage in option transactions and in doing so achieves similar objectives to what it would achieve through the sale or purchase of individual securities. A call option, upon payment of a premium, gives the purchaser of the option the right to buy, and the seller of the option the obligation to sell, the underlying security, index or other instrument at the exercise price. A put option gives the purchaser of the option, upon payment of a premium, the right to sell, and the seller the obligation to buy, the underlying security, index, or other instrument at the exercise price.

To seek to offset some of the risk of a potential decline in value of certain long positions, the Portfolio may also purchase put options on individual securities, broad-based securities indexes or certain exchange-traded funds (“ETFs”). The Portfolio may also seek to generate income from option premiums by writing (selling) options on a portion of the equity securities (including securities that are convertible into equity securities) in the Portfolio, on broad-based securities indexes, or certain ETFs.

When the Portfolio purchases an option, it pays a premium and an amount equal to that premium is recorded as an asset. When the Portfolio writes an option, it receives a premium and an amount equal to that premium is recorded as a liability. The asset or liability is adjusted daily to reflect the current market value of the option. If an option expires unexercised, the Portfolio realizes a gain or loss to the extent of the premium received or paid. If an option is exercised, the premium received or paid is recorded as an adjustment to the proceeds from the sale or the cost basis of the purchase. The difference between the premium and the amount received or paid on a closing purchase or sale transaction is also treated as a realized gain or loss. The cost of securities acquired through the exercise of call options is increased by premiums paid. The proceeds from securities sold through the exercise of put options are decreased by the premiums paid. Gain or loss on written options and purchased options is presented separately on the Statement of Operations as net realized gain or loss on written options and net realized gain or loss on purchased options, respectively.

Options written by the Portfolio do not typically give rise to counterparty credit risk since options written obligate the Portfolio and not the counterparty to perform. Exchange traded purchased options have minimal counterparty credit risk to the Portfolio since the exchange’s clearinghouse, as counterparty to such instruments, guarantees against a possible default.

As of June 30, 2022, the Portfolio had outstanding purchased options and/or written options as listed on the Schedule of Investments.

As of June 30, 2022, the Portfolio had outstanding derivative contracts which are reflected on the Statement of Assets and Liabilities as follows:

	ASSET DERIVATIVES	LIABILITY DERIVATIVES
Gross amounts at fair value:
Purchased options(1)	$75,093	$—
Written options(2)	—	4,482
	$75,093	$4,482

(1)Generally, the Statement of Assets and Liabilities location for purchased options is investments in securities, at value.

(2)Generally, the Statement of Assets and Liabilities location for written options is Options written, at value.

For the period ended June 30, 2022, the volume of derivative activity for the Portfolio is reflected below:*

	VOLUME
Forward foreign currency contracts	235,305
Purchased options	653
Written options	177

*Activity during the period is measured by opened number of contracts for options purchased or written and opened forward foreign currency contracts (measured in notional).

22   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Notes to Financial Statements (Unaudited)

Note 6 – Securities Lending

The Portfolio may loan one or more of its securities to broker-dealers and banks. Any such loan must be secured by collateral in cash or cash equivalents maintained on a current basis in an amount at least equal to the value of the securities loaned by the Portfolio. The Portfolio continues to receive the equivalent of the interest or dividends paid by the issuer on the securities loaned and also receives an additional return that may be in the form of a fixed fee or a percentage of the collateral. The additional return is disclosed on a net basis as Securities lending income in the Statement of Operations. Upon receipt of cash or cash equivalent collateral, the Portfolio’s securities lending agent invests the collateral into short term investments following investment guidelines approved by Calamos Advisors. The Portfolio records the investment of collateral as an asset (Investment in securities, at value or Restricted cash for collateral on securities loaned) and the value of the collateral as a liability (Collateral for securities loaned) on the Statement of Assets and Liabilities. If the value of the invested collateral declines below the value of the collateral deposited by the borrower, the Portfolio will record unrealized depreciation equal to the decline in value of the invested collateral. The Portfolio will pay reasonable fees to persons unaffiliated with the Portfolio for services in arranging these loans. The Portfolio has the right to call a loan and obtain the securities loaned at any time. The Portfolio does not have the right to vote the securities during the existence of the loan but could call the loan in an attempt to permit voting of the securities in certain circumstances. Upon return of the securities loaned, the cash or cash equivalent collateral will be returned to the borrower. In the event of bankruptcy or other default of the borrower, the Portfolio could experience both delays in liquidating the loan collateral or recovering the loaned securities and losses, including (a) possible decline in the value of the collateral or in the value of the securities loaned during the year while the Portfolio seeks to enforce its rights thereto, (b) possible subnormal levels of income and lack of access to income during this year, and (c) the expenses of enforcing its rights. In an effort to reduce these risks, the Portfolio’s security lending agent monitors and reports to Calamos Advisors on the creditworthiness of the firms to which the Portfolio lends securities.

The following table indicates the total amount of securities loaned by asset class, reconciled to the gross liability payable upon return of the securities loaned by the Portfolio as June 30, 2022.

Amount of Collateral Held in Short Term Investments and Restricted Cash	Amount of Non-Cash Collateral	Total Collateral	VALUE OF SECURITIES ON LOAN TO BROKER-DEALERS BANKS BY ASSET CLASS ON LOAN			Excess Amount Due To/(From) Counterparty
			Equity	Fixed Income	TOTAL
$1,366,030	$11,986	$1,378,016	$375,621	$966,107	$1,341,728	$36,288

Repurchase agreements involve the Portfolio purchasing securities from a seller, subject to the seller’s agreement to repurchase the securities at a mutually agreed upon date and price, under the terms of a Master Repurchase Agreement (“MRA”). During the term of a repurchase agreement, the value of the underlying securities held as collateral on behalf of the Portfolio, including accrued interest, is required to exceed the value of the repurchase agreement, including accrued interest. Collateral investments in repurchase agreements are collateralized by U.S. Treasury Bonds. The U.S. Treasury Bonds are held in a custody account at Citibank N.A., the Portfolio’s securities lending agent, on behalf of the Portfolio participating in the securities lending program. In the event the counterparty defaults on the repurchase agreement, the U.S. Treasury Bonds can either be maintained as part of the Portfolio or sold for cash. The Portfolio could suffer a loss to the extent that the proceeds from the sale of the underlying collateral held by the Portfolio is less than the repurchase price and the Portfolio’s costs associated with the delay and enforcement of the MRA. The Portfolio did not hold any repurchase agreements at June 30, 2022.

23

Notes to Financial Statements (Unaudited)

Note 7 – Fair Value Measurements

Various inputs are used to determine the value of the Portfolio’s investments. These inputs are categorized into three broad levels as follows:

•Level 1 – Prices are determined using inputs from unadjusted quoted prices from active markets (including securities actively traded on a securities exchange) for identical assets.

•Level 2 – Prices are determined using significant observable market inputs other than unadjusted quoted prices, including quoted prices of similar securities, fair value adjustments to quoted foreign securities, interest rates, credit risk, prepayment speeds, and other relevant data.

•Level 3 – Prices reflect unobservable market inputs (including the Portfolio’s own judgments about assumptions market participants would use in determining fair value) when observable inputs are unavailable.

Debt securities are valued based upon evaluated prices received from an independent pricing service or from a dealer or broker who makes markets in such securities. Pricing services utilize various observable market data and as such, debt securities are generally categorized as Level 2. The levels are not necessarily an indication of the risk or liquidity of the Portfolio’s investments.

The following is a summary of the inputs used in valuing the Portfolio’s holdings at fair value:

		LEVEL 1		LEVEL 2		LEVEL 3		TOTAL
Assets:
Convertible Bonds	$	—	$	4,418,333	$	—	$	4,418,333
Convertible Preferred Stocks		1,472,413		446,916		—		1,919,329
Common Stocks U.S.		19,215,809		—		—		19,215,809
Common Stocks Foreign		78,434		—		—		78,434
U.S. Government and Agency Securities		—		583,714		—		583,714
Purchased Options		75,093		—		—		75,093
Investment of Cash Collateral For Securities Loaned		—		1,366,030		—		1,366,030
Total	$	20,841,749	$	6,814,993	$	—	$	27,656,742
Liabilities:
Written Options	$	4,482	$	—	$	—	$	4,482
Total	$	4,482	$	—	$	—	$	4,482

24   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Financial Highlights

Selected data for a share outstanding throughout each period were as follows:

		(Unaudited) Six Months Ended June 30, 2022		Year Ended December 31,
				2021		2020		2019		2018		2017
PER SHARE OPERATING PERFORMANCE
Net asset value, beginning of period		$22.85		$20.57		$17.01		$14.01		$15.54		$14.24
Income from investment operations:
	Net investment income (loss)(a)	(0.01	)	(0.09	)	0.18		0.17		0.18		0.16
	Net realized and unrealized gain (loss)	(4.35	)	4.19		3.57		3.38		(0.85	)	2.03
Total from investment operations		(4.36	)	4.10		3.75		3.55		(0.67	)	2.19
Less distributions to common shareholders from:
	Net investment income	(0.06	)	(0.08	)	(0.09	)	(0.26	)	(0.21	)	(0.13	)
	Net realized gains	(1.67	)	(1.74	)	(0.10	)	(0.29	)	(0.65	)	(0.76	)
Total distributions		(1.73	)	(1.82	)	(0.19	)	(0.55	)	(0.86	)	(0.89	)
Net asset value, end of period		$16.76		$22.85		$20.57		$17.01		$14.01		$15.54
TOTAL RETURN APPLICABLE TO COMMON SHAREHOLDERS
Total investment return based on:(b)
	Net asset value(c)	(19.83	)%	21.40	%	22.43	%	25.56	%	(4.39	)%	15.51	%
RATIOS TO AVERAGE NET ASSETS APPLICABLE TO COMMON SHAREHOLDERS
	Net expenses	1.31	%(d)	1.20	%	1.29	%	1.35	%	1.35	%	1.48	%
	Net investment income (loss)	(0.15	)%(d)	(0.40	)%	1.01	%	1.09	%	1.15	%	1.05	%
SUPPLEMENTAL DATA
	Net assets applicable to common shareholders, end of period (000)	$27,449		$35,663		$32,254		$28,112		$24,041		$26,887
	Portfolio turnover rate	11	%	16	%	45	%	21	%	22	%	32	%

(a)Net investment income allocated based on average shares method.

(b)Performance figures of the Portfolio do not reflect fees charged pursuant to the terms of variable life insurance policies and variable annuity contracts. If they did, performance would be lower.

(c)Total return measures net investment income and capital gain or loss from portfolio investments assuming reinvestment of dividends and capital gains distributions.

(d)Annualized.

25

Report of Independent Registered Public Accounting Firm

To the Shareholders and Board of Trustees of
Calamos Advisors Trust

Results of Review of Interim Financial Information

We have reviewed the accompanying statement of assets and liabilities, including the schedule of investments, of Calamos Growth and Income Portfolio (the “Portfolio”), the sole portfolio constituting the Calamos Advisors Trust (the “Trust”), as of June 30, 2022, the related statements of operations, changes in net assets, and the financial highlights for the six-month period then ended, and the related notes (collectively referred to as the “interim financial information”). Based on our review, we are not aware of any material modifications that should be made to the accompanying interim financial information for it to be in conformity with accounting principles generally accepted in the United States of America.

We have previously audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States) (PCAOB), the statement of changes in net assets of the Portfolio for the year ended December 31, 2021 and the financial highlights for each of the five years in the period then ended, and in our report dated February 10, 2022, we expressed an unqualified opinion on such statement of changes in net assets and financial highlights.

Basis for Review Results

This interim financial information is the responsibility of the Portfolio’s management. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Portfolio in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our review in accordance with standards of the PCAOB. A review of interim financial information consists principally of applying analytical procedures and making inquiries of persons responsible for financial and accounting matters. It is substantially less in scope than an audit conducted in accordance with the standards of the PCAOB, the objective of which is the expression of an opinion regarding the financial statements and financial highlights taken as a whole. Accordingly, we do not express such an opinion.

August 9, 2022

Chicago, Illinois

We have served as the auditor of one or more Calamos investment companies since 2003.

26   CALAMOS GROWTH AND INCOME PORTFOLIO SEMIANNUAL REPORT

Trustee Approval of Management Agreement (Unaudited)

The Board of Trustees (“Board” or the “Trustees”) of Calamos Advisors Trust (“Trust”) oversees the management of Calamos Growth and Income Portfolio (“Portfolio”), a series of the Trust, and, as required by law, determines annually whether to continue the Trust’s management agreement with Calamos Advisors LLC (“Adviser”) pursuant to which the Adviser serves as the investment manager and administrator for the Portfolio. The “Independent Trustees,” who comprise more than 80% of the Board, have never been affiliated with the Adviser.

In connection with their most recent consideration regarding the continuation of the management agreement, the Trustees received and reviewed a substantial amount of information provided by the Adviser in response to detailed requests of the Independent Trustees and their independent legal counsel. In the course of their consideration of the agreement, the Independent Trustees were advised by their counsel, and in addition to meeting with management of the Adviser, they met separately in executive session with their counsel.

At a meeting held on June 29, 2022, based on their evaluation of the information referred to above and other information provided in this and previous meetings, the Trustees determined that the overall arrangements between the Trust and the Adviser on behalf of the Portfolio were fair in light of the nature, quality and extent of the services provided by the Adviser and its affiliates, the fees charged for those services and other matters that the Trustees considered relevant in the exercise of their business judgment. At that meeting, the Trustees, including all of the Independent Trustees, approved the continuation of the management agreement with respect to the Portfolio through July 31, 2023, subject to possible earlier termination as provided in the agreement.

In connection with its consideration of the management agreement, the Board considered, among other things: (i) the nature, quality and extent of the Adviser’s services, (ii) the investment performance of the Portfolio as well as performance information for comparable funds and other, comparable clients of the Adviser, (iii) the fees and other expenses paid by the Portfolio as well as expense information for comparable funds and for other, comparable clients of the Adviser, (iv) the profitability of the Adviser and its affiliates from their relationship with the Portfolio, (v) whether economies of scale may be realized as the Portfolio grows and whether potential economies may be shared, in some measure, with Portfolio investors and (vi) other benefits to the Adviser from its relationship with the Portfolio. In the Board’s deliberations, no single factor was responsible for the Board’s decision to approve continuation of the management agreement, and each Trustee may have afforded different weight to the various factors.

Nature, Quality and Extent of Services. The Board’s consideration of the nature, quality and extent of the Adviser’s services to the Portfolio took into account the knowledge gained from the Board’s meetings with the Adviser throughout the years. In addition, the Board considered: the Adviser’s long- term history of managing the Portfolio; the consistency of investment approach; the background and experience of the Adviser’s investment personnel responsible for managing the Portfolio; and the Adviser’s performance as administrator of the Portfolio, including, among other things, in the areas of brokerage selection, trade execution, compliance and shareholder communications. The Board also reviewed the Adviser’s resources and key personnel involved in providing investment management services to the Portfolio. The Board noted the personal investments that the Adviser’s key investment personnel have made in the Portfolio, which further aligns the interests of the Adviser and its personnel with those of the Portfolio’s shareholders. In addition, the Board considered compliance reports about the Adviser from the Portfolio’s Chief Compliance Officer.

The Board also considered the information provided by the Adviser regarding the Portfolio’s performance and the steps the Adviser is taking to improve performance. In particular, the Board noted the additional personnel added to the Adviser’s investment team, which includes portfolio managers, research analysts, research associates and risk management personnel. The Board also noted the Adviser’s significant investment into its infrastructure and investment processes.

Investment Performance of the Portfolio. The Board considered the Portfolio’s investment performance over the one-, three-, five- and ten-year periods ended March 31, 2022, including how the Portfolio performed compared to the average performance of a group of comparable funds (the Portfolio’s “Category”) selected by an independent third-party service provider.

The Board considered that the Portfolio outperformed its Category average for all periods.

Costs of Services Provided and Profits Realized by the Adviser. Using information provided by an independent third-party service provider, the Board evaluated the Portfolio’s actual management fee rate compared to the median management fee rate for other mutual funds similar in size, character and investment strategy (the Portfolio’s “Expense Group”), and the Portfolio’s total expense ratio compared to the median total expense ratio of the Portfolio’s Expense Group.

27

Trustee Approval of Management Agreement (Unaudited)

The Board also reviewed the Adviser’s management fee rates for its institutional separate accounts and sub-advisory accounts with comparable investment strategies. The Board took into account that although, generally, the rates of fees paid by institutional clients or for sub-advisory services were lower than the rates of fees paid by the Portfolio, the differences reflected the Adviser’s greater level of responsibilities and significantly broader scope of services regarding the Portfolio, the more extensive regulatory obligations and risks associated with managing the Portfolio, and other financial considerations with respect to creation and sponsorship of the Portfolio. The Board considered factors that lead to more expenses for registered funds including but not limited to: (i) capital expenditures to establish a fund, (ii) length of time to reach critical mass, and the related expenses, (iii) higher servicing costs of intermediaries and shareholders, (iv) higher redemption rates of assets under management, (v) entrepreneurial risk assumed by the Adviser and (vi) greater exposure to “make whole” errors.

The Board also considered the Adviser’s costs in serving as the Portfolio’s investment adviser and manager, including but not limited to costs associated with technology, infrastructure and compliance necessary to manage the Portfolio. The Board reviewed the Adviser’s methodology for allocating costs among the Adviser’s lines of business. The Board also considered information regarding the structure of the Adviser’s compensation program for portfolio managers, analysts and certain other employees, and the relationship of such compensation to the attraction and retention of quality personnel. Finally, the Board reviewed information on the profitability of the Adviser in serving as the Portfolio’s investment manager and of the Adviser and its affiliates in all of their relationships with the Portfolio, as well as an explanation of the methodology utilized in allocating various expenses among the Portfolio and the Adviser’s other business units. Data was provided to the Board with respect to profitability, both on a pre- and post-marketing cost basis. The Board reviewed the financial statements of the Adviser’s parent company and discussed its corporate structure.

The Board considered that the Portfolio’s management fee rate and total expense ratio are higher than the respective medians of the Portfolio’s Expense Group. The Board reviewed the Portfolio’s expenses in light of its performance record.

Economies of Scale. The Board considered whether the Portfolio’s management fee shares with shareholders potential economies of scale that may be achieved by the Adviser. The Board also considered the benefits accruing to shareholders from the Adviser’s investments into its infrastructure and investment processes.

Other Benefits Derived from the Relationship with the Portfolio. The Board also considered other benefits that accrue to the Adviser and its affiliates from their relationship with the Portfolio. The Board concluded that while the Adviser may potentially benefit from its relationship with the Portfolio in ways other than the fees payable by the Portfolio, the Portfolio also may benefit from its relationship with the Adviser in ways other than the services to be provided by the Adviser and its affiliates pursuant to their agreements with the Portfolio and the fees payable by the Portfolio.

The Board also considered the Adviser’s use of a portion of the commissions paid by the Portfolio on its portfolio brokerage transactions to obtain research products and services benefiting the Portfolio and/or other clients of the Adviser and concluded, based on reports from the Portfolio’s Chief Compliance Officer, that the Adviser’s use of “soft” commission dollars to obtain research products and services was consistent with regulatory requirements.

After full consideration of the above factors as well as other factors that were instructive in their consideration, the Trustees, including all of the Independent Trustees, concluded that the continuation of the management agreement for the Portfolio with the Adviser was in the best interest of the Portfolio and its shareholders.

2020 Calamos Court

Naperville, IL 60563-2787

800.582.6959

www.calamos.com

© 2022 Calamos Investments LLC. All Rights Reserved.
Calamos^® and Calamos Investments^® are registered trademarks of Calamos Investments LLC.

KCLSAN 2146 2022

This report, including the audited financial statements contained herein, is submitted for general information for the shareholders of the Portfolio. The report is not authorized for distribution to prospective investors in the Portfolio unless accompanied by a currently effective prospectus of the Portfolio.

A description of the Calamos Proxy Voting Policies and Procedures and the Portfolio’s proxy voting record for the 12-month period ended June 30 are available free of charge upon request by calling 800.582.6959, by visiting the Calamos Web site at www.calamos.com, or by writing Calamos at: Calamos Investments, Attn: Client Services, 2020 Calamos Court, Naperville, IL 60563. The Portfolio’s proxy voting record is also available free of charge by visiting the SEC Web site at www.sec.gov.

The Portfolio files a complete list of their portfolio holdings with the SEC for the first and third quarters of each fiscal year as an exhibit to its report on Form N-PORT. The Portfolio’s Form N-PORT reports are available on the commission’s website at www.sec.gov.

Item 1(b).

Registrant has included in its Rule 30e-3(c) notice only the disclosures specified by Rule 30e-3(c)(1) and (2). Therefore, Registrant has not included a copy of the notice herewith.

ITEM 2. CODE OF ETHICS.

Not applicable. The information required by this Item 2 is only required in an annual report on this Form N-CSR.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable. The information required by this Item 3 is only required in an annual report on this Form N-CSR.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable. The information required by this Item 4 is only required in an annual report on this Form N-CSR.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable.

ITEM 6. SCHEDULE OF INVESTMENTS

(a) Included in the Report to Shareholders in Item 1.

(b) Not Applicable.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

No material changes.

ITEM 11. CONTROLS AND PROCEDURES.

a) The registrant’s principal executive officer and principal financial officer have evaluated the registrant’s disclosure controls and procedures within 90 days of this filing and have concluded that the registrant’s disclosure controls and procedures were effective, as of that date, in ensuring that information required to be disclosed by the registrant in this Form N-CSR was recorded, processed, summarized, and reported timely.

b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) that occurred during the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 12. DISCLOSURE OF SECURITIES LENDING ACTIVITIES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable.

ITEM 13. EXHIBITS.

(a)(1) Code of Ethics — Not applicable for this semiannual report.

(a)(2)(i) Certification of Principal Executive Officer.

(a)(2)(ii) Certification of Principal Financial Officer.

(b) Certifications pursuant to Section 906 of the Sarbanes Oxley Act of 2002.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Calamos Advisors Trust

By:	/s/ John P. Calamos, Sr.
Name:	John P. Calamos, Sr.
Title:	Principal Executive Officer
Date:	August 16, 2022
By:	/s/ Thomas E. Herman
Name:	Thomas E. Herman
Title:	Principal Financial Officer
Date:	August 16, 2022

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

Calamos Advisors Trust

By:	/s/ John P. Calamos, Sr.
Name:	John P. Calamos, Sr.
Title:	Principal Executive Officer
Date:	August 16, 2022
By:	/s/ Thomas E. Herman
Name:	Thomas E. Herman
Title:	Principal Financial Officer
Date:	August 16, 2022