Exhibit 99.1

Vistra Reports 2020 Results Above Top End of Raised Guidance Range and Estimates One-Time Impact of Winter Storm Uri

IRVING, Texas — Feb. 26, 2021 — Vistra (NYSE: VST):

2020 Financial Highlights

“Vistra executed exceptionally well in the face of challenges brought on by the global pandemic, delivering 2020 Adjusted EBITDA from Ongoing Operations nearly 10% higher than our original guidance midpoint. 2020 also marks the fifth year in a row that Vistra’s adjusted EBITDA has exceeded our financial guidance midpoint with our outperformance totaling more than $500 million over this period,” said Curt Morgan, Vistra’s chief executive officer. “We have proven that when we control our destiny, we consistently over-perform. The challenges brought on by the global pandemic in 2020 and the historic winter storm in Texas last week have tested our business model. We continue to believe that our integrated operations, prioritizing a strong balance sheet and conservative liquidity management, is the right model to remain resilient through these challenges while creating value for our stakeholders over the long-term.”

Winter Storm Uri

In February 2021, the U.S. experienced winter storm Uri, bringing extreme cold temperatures to the central U.S., including Texas. This severe weather resulted in surging demand for power, gas supply shortages, operational challenges for generators, and a significant load shed event (i.e., involuntary outages to customers across the system for varying periods of time) that was ordered by ERCOT beginning on Feb. 15, 2021 and continuing through Feb. 18, 2021. In anticipation of and during the storm, Vistra:

Vistra – Press Release

Feb. 26, 2021, Page 2

The overall financial impact from winter storm Uri is still being calculated, but Vistra expects it will have a material adverse impact on its financial results driven by generation output being constrained due to challenges with receiving a steady supply of fuel for some plants as well as challenges with handling fuel already on site given the freezing conditions. As a result of these challenges, Vistra had to procure power in the ERCOT market at prices at or near the price cap to meet its supply obligations.

2021 Guidance and Capital Allocation

As a result of Winter Storm Uri hitting Texas last week, Vistra is not able to reaffirm or adjust its 2021 guidance as Vistra does not yet have enough information to provide an exact estimate of the one-time financial impact of this unprecedented winter storm. While the financial impacts of Winter Storm Uri to Vistra are not yet finalized, Vistra management preliminarily estimates the one-time adverse impact will be in the range of ~$900 million to $1,300 million. This estimated range is preliminary and based on currently available information and management estimates. The final amount of the estimated loss is subject to a variety of factors including, but not limited to, outstanding pricing, load, and settlement data from ERCOT, potential state corrective action, or the outcome of potential litigation arising from this event. Vistra will provide a further update as information is available, the timing of which is currently unknown.

Vistra continues to be committed to our capital allocation plan, including our recommended dividend trajectory and debt reduction expectations. Vistra will provide a further update on 2021 capital allocation as estimates of the financial impact of Winter Storm Uri are finalized, the timing of which is currently unknown. Vistra remains confident in its ability to generate significant Adjusted EBITDA and Free Cash Flow before Growth over the long-term, supporting our diverse capital allocation plans.

Liquidity

As of Dec. 31, 2020, Vistra had total available liquidity of ~$2,399 million, including cash and cash equivalents of $406 million, $1,988 million of availability under its revolving credit facility, and $5 million of availability under its various bi-lateral letter of credit facilities. Winter Storm Uri resulted in Vistra being required to post a significant amount of collateral, including to ERCOT, clearinghouses for natural gas and power transactions, and other trading counterparties. Despite these posting requirements, Vistra consistently maintained, and it continues to maintain, sufficient liquidity to conduct its operations in the ordinary course. As of Feb. 25, 2021, Vistra had more than $1.5 billion of cash and availability under its revolving credit facility.

2020 Capital Allocation Highlights

2020 Portfolio Transformation and Growth Investments

Vistra – Press Release

Feb. 26, 2021, Page 3

2020 ESG Highlights

Summary of Financial Results for the Fourth Quarter Ended Dec. 31, 2020 and Full Year 2020

For the three months ended Dec. 31, 2020, Vistra reported a Net Loss of $27 million, Net Loss from Ongoing Operations¹ of $14 million, and Ongoing Operations Adjusted EBITDA¹ of $802 million. Vistra’s fourth quarter 2020 Net Income/(Loss) of $(27) million was $260 million lower than fourth quarter 2019 Net Income/(Loss) of $233 million, driven primarily by a decrease in unrealized net gains on hedging transactions. Vistra’s fourth quarter Adjusted EBITDA from Ongoing Operations was $27 million higher than fourth quarter 2019 results, primarily driven by the addition of Ambit.

Vistra reported fourth quarter Adjusted EBITDA from the Retail segment of $411 million, $68 million higher than fourth quarter 2019 results, driven by strong margin performance in ERCOT and the addition of Ambit. Fourth quarter Adjusted EBITDA from the generation segments², on an aggregate basis, totaled $391 million, $41 million lower than fourth quarter 2019 results driven by lower capacity revenue in the East segment.

Vistra – Press Release

Feb. 26, 2021, Page 4

For the full year of 2020, Vistra reported Net Income of $624 million, Net Income from Ongoing Operations¹ of $725 million, and Ongoing Operations Adjusted EBITDA¹ of $3,766 million. Vistra’s Net Income for the full year of 2020 was $302 million lower than full year 2019 Net Income, driven primarily by a decrease in unrealized gains on hedging transactions. Ongoing Operations Adjusted EBITDA for the full year of 2020 was $373 million higher than the full year of 2019, driven primarily by the additions of Crius and Ambit and strong ERCOT margin performance, partially offset by milder weather in the Retail segment, and higher margins in the Texas, East, and Sunset segments partially offset by lower capacity revenues in the collective generation segments.²

Earnings Webcast

Vistra will host a conference call and webcast today, Feb. 26, 2021, beginning at 8 a.m. ET (7 a.m. CT) to discuss these results and related matters. The live webcast and the accompanying slides that will be discussed on the call can be accessed via the investor relations section of Vistra’s website at www.vistracorp.com under “Investor Relations” and then “Events & Presentations.” Participants can also listen by phone by registering here prior to the start time of the call to receive a conference call dial-in number. A replay of the webcast will be available on the Vistra website for one year following the live event.

About Non-GAAP Financial Measures and Items Affecting Comparability

“Adjusted EBITDA” (EBITDA as adjusted for unrealized gains or losses from hedging activities, tax receivable agreement impacts, reorganization items, and certain other items described from time to time in Vistra’s earnings releases),“Adjusted Free Cash Flow before Growth” (or “Adjusted FCFbG”) (cash from operating activities excluding changes in margin deposits and working capital and adjusted for capital expenditures (including capital expenditures for growth investments), other net investment activities, and other items described from time to time in Vistra’s earnings releases), “Ongoing Operations Adjusted EBITDA” (adjusted EBITDA less adjusted EBITDA from Asset Closure segment), “Net Income from Ongoing Operations” (net income less net income from Asset Closure segment), “Ongoing Operations Adjusted Free Cash Flow before Growth” or “Ongoing Operations Adjusted FCFbG” (adjusted free cash flow before growth less cash flow from operating activities from Asset Closure segment before growth), are “non-GAAP financial measures.” A non-GAAP financial measure is a numerical measure of financial performance that excludes or includes amounts so as to be different than the most directly comparable measure calculated and presented in accordance with GAAP in Vistra’s consolidated statements of operations, comprehensive income, changes in stockholders’ equity, and cash flows. Non-GAAP financial measures should not be considered in isolation or as a substitute for the most directly comparable GAAP measures. Vistra’s non-GAAP financial measures may be different from non-GAAP financial measures used by other companies.

Vistra uses Adjusted EBITDA as a measure of performance and believes that analysis of its business by external users is enhanced by visibility to both Net Income prepared in accordance with GAAP and Adjusted EBITDA. Vistra uses Adjusted Free Cash Flow before Growth as a measure of liquidity and believes that analysis of its ability to service its cash obligations is supported by disclosure of both cash provided by (used in) operating activities prepared in accordance with GAAP as well as Adjusted Free Cash Flow before Growth. Vistra uses Ongoing Operations Adjusted EBITDA as a measure of performance and Ongoing Operations Adjusted Free Cash Flow before Growth as a measure of liquidity and Vistra’s management and Board have found it informative to view the Asset Closure segment as separate and distinct from Vistra’s ongoing operations. Vistra uses Net Income from Ongoing Operations as a non-GAAP measure that is most comparable to the GAAP measure Net Income in order to illustrate the company’s Net Income excluding the effects of the Asset Closure segment, as well as a measure to compare to Ongoing Operations Adjusted EBITDA. The schedules attached to this earnings release reconcile the non-GAAP financial measures to the most directly comparable financial measures calculated and presented in accordance with U.S. GAAP.

Media

Meranda Cohn

214-875-8004

Media.Relations@vistracorp.com

Analysts

Molly Sorg

214-812-0046

Investor@vistracorp.com

Vistra – Press Release

Feb. 26, 2021, Page 5

About Vistra

Vistra (NYSE: VST) is a leading, Fortune 275 integrated retail electricity and power generation company based in Irving, Texas, providing essential resources for customers, commerce, and communities. Vistra combines an innovative, customer-centric approach to retail with safe, reliable, diverse, and efficient power generation. The company brings its products and services to market in 20 states and the District of Columbia, including six of the seven competitive wholesale markets in the U.S. and markets in Canada and Japan, as well. Serving nearly 4.3 million residential, commercial, and industrial retail customers with electricity and natural gas, Vistra is one of the largest competitive residential electricity providers in the country and offers over 50 renewable energy plans. The company is also the largest competitive power generator in the U.S. with a capacity of approximately 39,000 megawatts powered by a diverse portfolio, including natural gas, nuclear, solar, and battery energy storage facilities. In addition, the company is a large purchaser of wind power. The company is currently constructing a 400-MW/1,600-MWh battery energy storage system in Moss Landing, California, the largest of its kind in the world. Vistra is guided by four core principles: we do business the right way, we work as a team, we compete to win, and we care about our stakeholders, including our customers, our communities where we work and live, our employees, and our investors. Learn more about our environmental, social, and governance efforts and read the company’s sustainability report at https://www.vistracorp.com/sustainability/.

Cautionary Note Regarding Forward-Looking Statements

The information presented herein includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements, which are based on current expectations, estimates and projections about the industry and markets in which Vistra Corp. (“Vistra”) operates and beliefs of and assumptions made by Vistra’s management, involve risks and uncertainties, which are difficult to predict and are not guarantees of future performance, that could significantly affect the financial results of Vistra. All statements, other than statements of historical facts, that are presented herein, or in response to questions or otherwise, that address activities, events or developments that may occur in the future, including such matters as activities related to our financial or operational projections, the potential impacts of the COVID-19 pandemic on our results of operations, financial condition and cash flows, projected synergy, value lever and net debt targets, capital allocation, capital expenditures, liquidity, projected Adjusted EBITDA to free cash flow conversion rate, dividend policy, business strategy, competitive strengths, goals, future acquisitions or dispositions, development or operation of power generation assets, market and industry developments and the growth of our businesses and operations (often, but not always, through the use of words or phrases, or the negative variations of those words or other comparable words of a future or forward-looking nature, including, but not limited to: “intends,” “plans,” “will likely,” “unlikely,” “believe,” “confident”, “expect,” “seek,” “anticipate,” “estimate,” “continue,” “will,” “shall,” “should,” “could,” “may,” “might,” “predict,” “project,” “forecast,” “target,” “potential,” “goal,” “objective,” “guidance” and “outlook”),are forward-looking statements. Readers are cautioned not to place undue reliance on forward-looking statements. Although Vistra believes that in making any such forward-looking statement, Vistra’s expectations are based on reasonable assumptions, any such forward-looking statement involves uncertainties and risks that could cause results to differ materially from those projected in or implied by any such forward-looking statement, including, but not limited to: (i) adverse changes in general economic or market conditions (including changes in interest rates) or changes in political conditions or federal or state laws and regulations; (ii) the ability of Vistra to execute upon its contemplated strategic, capital allocation, and performance initiatives and to successfully integrate acquired businesses; (iii) actions by credit ratings agencies; (iv) the severity, magnitude and duration of pandemics, including the COVID-19 pandemic, and the resulting effects on our results of operations, financial condition and cash flows; (v) the severity, magnitude and duration of extreme weather events, including winter storm Uri, and the resulting effects on our results of operations, financial condition and cash flows; and (vi) those additional risks and factors discussed in reports filed with the Securities and Exchange Commission by Vistra from time to time, including the uncertainties and risks discussed in the sections entitled “Risk Factors” and “Forward-Looking Statements” in Vistra’s annual report on Form 10-K for the year ended December 31, 2020 and any subsequently filed quarterly reports on Form 10-Q.

Any forward-looking statement speaks only at the date on which it is made, and except as may be required by law, Vistra will not undertake any obligation to update any forward-looking statement to reflect events or circumstances after the date on which it is made or to reflect the occurrence of unanticipated events. New factors emerge from time to time, and it is not possible to predict all of them; nor can Vistra assess the impact of each such factor or the extent to which any factor, or combination of factors, may cause results to differ materially from those contained in any forward-looking statement.

VISTRA CORP.

CONSOLIDATED STATEMENTS OF OPERATIONS

(Millions of Dollars, Except Per Share Amounts)

VISTRA CORP.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Millions of Dollars)

VISTRA CORP.

CONSOLIDATED STATEMENTS OF CASH FLOWS

(Millions of Dollars)

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NON-GAAP RECONCILIATIONS—ADJUSTED EBITDA

FOR THE THREE MONTHS ENDED DECEMBER 31, 2020

(Unaudited) (Millions of Dollars)

VISTRA CORP.

NON-GAAP RECONCILIATIONS—ADJUSTED EBITDA

FOR THE YEAR ENDED DECEMBER 31, 2020

(Unaudited) (Millions of Dollars)

VISTRA CORP.

NON-GAAP RECONCILIATIONS—ADJUSTED EBITDA

FOR THE THREE MONTHS ENDED DECEMBER 31, 2019

(Unaudited) (Millions of Dollars)

VISTRA CORP.

NON-GAAP RECONCILIATIONS—ADJUSTED EBITDA

FOR THE YEAR ENDED DECEMBER 31, 2019

(Unaudited) (Millions of Dollars)

VISTRA CORP.

NON-GAAP RECONCILIATIONS—ADJUSTED FREE CASH FLOW

FOR YEAR ENDED DECEMBER 31, 2020

(Unaudited) (Millions of Dollars)