Exhibit 99.1

Vistra Energy Announces Capital Allocation Plan;

Reports Third Quarter 2018 Results; Narrows 2018 and 2019 Guidance

IRVING, Texas, November 2, 2018 — Vistra Energy Corp. (NYSE: VST):

Third Quarter Highlights

Vistra Energy - Press Release

November 2, 2018, Page 2

Summary of Financial Results for the Third Quarter Ended September 30, 2018 (in millions)

For the three months ended September 30, 2018, Vistra reported net income from ongoing operations of $335 million and adjusted EBITDA from ongoing operations of $1,153 million.

Year-to-date, Vistra reported net income from ongoing operations of $154 million and adjusted EBITDA from ongoing operations of $2,069 million. Excluding the impact to adjusted EBITDA of negative $20 million during the period resulting from the partial buybacks of the Odessa Power Plant earnout in February and May, Vistra’s year-to-date adjusted EBITDA from ongoing operations would have been $2,089 million. When the Odessa earnout buybacks were executed, Vistra estimated the economic benefit of the transactions, net of the premiums paid, would be approximately $25 million.

Curt Morgan, Vistra’s chief executive officer, commented, “We are excited to announce Vistra’s capital allocation program, including authorization to allocate an additional $1.25 billion of capital toward share repurchases and to initiate a recurring dividend in the first quarter of 2019. Today’s capital allocation announcements are part of an ongoing commitment of returning capital to shareholders—all with a target to achieve 2.5 times net debt to EBITDA by year-end 2020. Vistra’s resilient EBITDA production and robust free cash flow conversion in 2018 and expected in 2019 and beyond, stemming from the stability of our integrated model and substantial merger value, support this diverse capital allocation plan including a growing dividend, which we believe will create meaningful value for our shareholders.”

Guidance

Vistra Energy - Press Release

November 2, 2018, Page 3

Vistra Energy is narrowing and reaffirming its 2018 Ongoing Operations guidance ranges, forecasting Ongoing Operations Adjusted EBITDA of $2,750 to $2,850 million and Ongoing Operations Adjusted FCFbG of $1,450 to $1,550 million. The 2018 guidance ranges were developed utilizing improved ERCOT forward curves as of March 29, 2018. The ranges reflect Vistra’s results on a stand-alone basis for the period prior to April 9, 2018 and anticipated results of the combined company for the period from April 9 through December 31, 2018.

Vistra is also narrowing and updating its 2019 Ongoing Operations guidance ranges, forecasting Ongoing Operations Adjusted EBITDA of $3,220 to $3,420 million and Ongoing Operations Adjusted FCFbG of $2,100 to $2,300 million.

Initial Share Repurchase Program

As of November 1, 2018, Vistra has completed the initial $500 million share repurchase program authorized by its board of directors on June 12, 2018. Vistra purchased approximately 21.4 million shares for an average price of $23.36 per share.

Financing Update

In August 2018, Vistra Energy used the net proceeds from the issuance by Vistra Operations Company LLC, a wholly owned, indirect subsidiary of Vistra Energy, of $1,000 million aggregate principal amount of 5.50% senior notes due 2026, the net proceeds from a $350 million accounts receivable securitization program, and cash on hand to fund cash tender offers to purchase $1,542 million aggregate principal amount of the following senior notes that Vistra Energy assumed in the merger with Dynegy:

As a result of the transaction, Vistra reduced its annual interest expense by approximately $56 million and extended maturities.

Liquidity

As of September 30, 2018, Vistra had total available liquidity of approximately $2.101 billion, including cash and cash equivalents of $811 million and $1,290 million of availability under its revolving credit facility, which remained undrawn but had $1,210 million of letters of credit outstanding as of September 30, 2018.

Plant Retirement

Vistra announced on August 24, 2018 the planned retirement of its 51-megawatt waste coal facility, Northeastern Power Company, due to its uneconomic operations and negative financial outlook. The plant was retired on October 24, 2018.

Vistra Energy - Press Release

November 2, 2018, Page 4

Earnings Webcast

Vistra will host a webcast today, November 2, 2018, beginning at 8 a.m. ET (7 a.m. CT) to discuss these results and related matters. The live, listen-only 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.vistraenergy.com. 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 obligations, reorganization items, and certain other items described from time to time in Vistra Energy’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, preferred stock dividends, and other items described from time to time in Vistra Energy’s earnings releases), “Ongoing Operations Adjusted EBITDA” (adjusted EBITDA less adjusted EBITDA from Asset Closure segment) and “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 Energy’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 Energy’s non-GAAP financial measures may be different from non-GAAP financial measures used by other companies.

Vistra Energy 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 Energy 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 Energy 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 Energy’s management and board of directors have found it informative to view the Asset Closure segment as separate and distinct from Vistra Energy’s ongoing operations. 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

Allan Koenig

214-875-8004

Media.Relations@vistraenergy.com

Analysts

Molly Sorg

214-812-0046

Investor@vistraenergy.com

About Vistra Energy

Vistra Energy (NYSE: VST) is a premier, integrated power company based in Irving, Texas, combining an innovative, customer-centric approach to retail with a focus on safe, reliable, and efficient power generation. Through its retail and generation businesses which include TXU Energy, Homefield Energy, Dynegy, and Luminant, Vistra operates in 12 states and six of the seven competitive markets in the U.S., with about 6,000 employees. Vistra’s retail brands serve approximately 2.9 million residential, commercial, and industrial customers across five top retail states, and its generation fleet totals approximately 41,000 megawatts of highly efficient generation capacity, with a diverse portfolio of natural gas, nuclear, coal, and solar facilities.

Vistra Energy - Press Release

November 2, 2018, Page 5

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 Energy Corp. (“Vistra Energy”) operates and beliefs of and assumptions made by Vistra Energy’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 Energy. 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, 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,” “expect,” “seek,” “anticipate,” “estimate,” “continue,” “will,” “shall,” “should,” “could,” “may,” “might,” “predict,” “project,” “forecast,” “target,” “potential,” “forecast,” “goal,” “objective,” “guidance” and “outlook”),are forward-looking statements. Readers are cautioned not to place undue reliance on forward-looking statements. Although Vistra Energy believes that in making any such forward-looking statement, Vistra Energy’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 Energy to execute upon the contemplated strategic and performance initiatives (including the risk that Vistra Energy’s and Dynegy’s respective businesses will not be integrated successfully or that the cost savings, synergies and growth from the merger will not be fully realized or may take longer than expected to realize); (iii) actions by credit ratings agencies and (iv) those additional risks and factors discussed in reports filed with the Securities and Exchange Commission (“SEC”) by Vistra Energy from time to time, including the uncertainties and risks discussed in the sections entitled “Risk Factors” and “Forward-Looking Statements” in Vistra Energy’s quarterly report on Form 10-Q for the fiscal quarter ended June 30, 2018 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 Energy 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 Energy 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 Energy - Press Release

November 2, 2018, Page 6

VISTRA ENERGY CORP.

CONDENSED STATEMENTS OF CONSOLIDATED INCOME (LOSS)

(Unaudited) (Millions of Dollars, Except Per Share Amounts)

Vistra Energy - Press Release

November 2, 2018, Page 7

VISTRA ENERGY CORP.

CONDENSED STATEMENTS OF CONSOLIDATED CASH FLOWS

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 8

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - SEPTEMBER 2018 QTD ADJUSTED EBITDA

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 9

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - SEPTEMBER 2018 YTD ADJUSTED EBITDA

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 10

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - SEPTEMBER 2017 QTD ADJUSTED EBITDA

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 11

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - SEPTEMBER 2017 YTD ADJUSTED EBITDA

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 12

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - 2018 GUIDANCE

(Unaudited) (Millions of Dollars)

Vistra Energy - Press Release

November 2, 2018, Page 13

VISTRA ENERGY CORP.

NON-GAAP RECONCILIATIONS - 2019 GUIDANCE

(Unaudited) (Millions of Dollars)