Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

Assets and liabilities measured at fair value on a recurring basis consisted of the following at the respective balance sheet dates shown below:

	December 31, 2024										December 31, 2023
	Level 1		Level 2		Level 3 (a)		Reclass (a)		Total		Level 1		Level 2		Level 3 (a)		Reclass (a)		Total
	(in millions)
Assets:
Commodity contracts (b)	$	1,923	$	462	$	841	$	5	$	3,231	$	2,886	$	628	$	630	$	14	$	4,158
Interest rate swaps (b)	—		96		—		—		96		—		64		—		—		64
NDTs – equity securities (c)(d)	1,560		—		—		—		1,560		638		—		—		—		638
NDTs – debt securities (c)(e)	83		1,976		—		—		2,059		—		734		—		—		734
Sub-total	$	3,566	$	2,534	$	841	$	5	6,946		$	3,524	$	1,426	$	630	$	14	5,594
Assets measured at net asset value (f):
NDTs – equity securities (c)(d)(f)									821										579
Total assets									$	7,767									$	6,173
Liabilities:
Commodity contracts (b)	$	2,118	$	975	$	1,593	$	5	$	4,691	$	3,815	$	1,395	$	1,674	$	14	$	6,898
Interest rate swaps (b)	—		27		—		—		27		—		48		—		—		48
Total liabilities	$	2,118	$	1,002	$	1,593	$	5	$	4,718	$	3,815	$	1,443	$	1,674	$	14	$	6,946

____________

(a)Fair values for each level are determined on a contract basis, but certain contracts are in both an asset and a liability position. This reclassification represents the adjustment needed to reconcile to the gross amounts presented in the consolidated balance sheets.

(b)See Note 11 for additional information.

(c)NDT assets represent securities held for the purpose of funding the future retirement and decommissioning of our nuclear generation facilities. These investments include equity, debt and other fixed-income securities consistent with investment rules established by the NRC and the PUCT. The NDT investments are included in Investments in the consolidated balance sheets. There were no significant concentrations of credit risk from an individual counterparty or groups of counterparties in our NDT portfolio as of December 31, 2024.

(d)The investment objective for NDT equity securities is to invest tax efficiently and to match the performance of the S&P 500 Index for U.S. equity investments and the MSCI EAFE Index for non-U.S. equity investments.

(e)The investment objective for NDT debt securities is to invest in a diversified, high quality, tax efficient portfolio. The debt securities are weighted with government and investment grade corporate bonds. Other investable debt securities include, but are not limited to, municipal bonds, high yield bonds, securitized bonds, non-U.S. developed bonds, emerging market bonds, loans and treasury inflation-protected securities. The debt securities had an average coupon rate of 3.99% and 3.19% as of December 31, 2024 and 2023, respectively, and an average maturity of 7 years and 11 years as of December 31, 2024 and 2023, respectively. NDT debt securities held as of December 31, 2024 mature as follows: $1.045 billion in one to five years, $599 million in five to 10 years and $415 million after 10 years.

(f)Net asset value is a practical expedient used for the classification of assets that do not have readily determinable fair values and therefore are not classified in the fair value hierarchy. This amount is presented to permit reconciliation of this table to the amounts presented in the consolidated balance sheets.

As of December 31, 2024 and 2023, all of the Retirement Plan assets were measured at fair value using the net asset value per share (or its equivalent) except as noted and consisted of the following:

	December 31,
	2024		2023
	(in millions)
Asset Category:
Cash commingled trusts	$	6	$	4
Equity securities:
Global equities	86		82
Fixed income securities:
Corporate bonds (a)	79		82
Government bonds	42		54
Other (b)	28		18
Real estate	27		28
Hedge funds	17		17
Total assets measured at net asset value	$	285	$	285

___________

(a)Substantially all corporate bonds are rated investment grade by a major ratings agency such as Moody's.

(b)Consists primarily of high-yield bonds, emerging market debt, bank loans, securitized bonds and private investment grade fixed income.

Schedule of Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation

The following tables present the fair value of the Level 3 assets and liabilities by major contract type and the significant unobservable inputs used in the valuations as of December 31, 2024 and 2023:

December 31, 2024
	Fair Value
Contract Type (a)	Assets		Liabilities		Total, Net		Valuation Technique	Significant Unobservable Input	Range (b)							Average (b)
	(in millions)
Electricity purchases and sales	$	606	$	(1,399)	$	(793)	Income Approach	Hourly price curve shape (c)	$	—		to	$	95		$	48
									MWh
								Illiquid delivery periods for hub power prices (d)	$	25		to	$	140		$	83
									MWh
								Market Heat Rates (d)	$	30		to	$	150		$	90
									MWh
Options	6		(139)		(133)		Option Pricing Model	Natural gas to power correlation (e)	10		%	to	100		%	55		%
								Power and natural gas volatility (e)	5		%	to	710		%	358		%
Financial transmission rights/Congestion revenue rights	190		(25)		165		Market Approach (f)	Illiquid price differences between settlement points (g)	$	(35)		to	$	20		$	(8)
									MWh
Natural gas	29		(30)		(1)		Income Approach	Natural gas basis (h)	$	—		to	$	10		$	5
									MMBtu
								Illiquid delivery periods (i)	$	—		to	$	5		$	2
									MMBtu
Other (j)	10		—		10
Total	$	841	$	(1,593)	$	(752)

December 31, 2023
	Fair Value
Contract Type (a)	Assets		Liabilities		Total, Net		Valuation Technique	Significant Unobservable Input	Range (b)							Average (b)
	(in millions)
Electricity purchases and sales	$	449	$	(1,273)	$	(824)	Income Approach	Hourly price curve shape (c)	$	—		to	$	85		$	44
									MWh
								Illiquid delivery periods for hub power prices and Heat Rates (d)	$	30		to	$	110		$	71
									MWh
Options	1		(237)		(236)		Option Pricing Model	Natural gas to power correlation (e)	10		%	to	100		%	55		%
								Power and natural gas volatility (e)	10		%	to	870		%	441		%
Financial transmission rights/Congestion revenue rights	157		(34)		123		Market Approach (f)	Illiquid price differences between settlement points (g)	$	(85)		to	$	25		$	(30)
									MWh
Natural gas	9		(112)		(103)		Income Approach	Natural gas basis (h)	$	—		to	$	15		$	6
									MMBtu
								Illiquid delivery periods (i)	$	—		to	$	5		$	4
									MMBtu
Other (j)	14		(18)		(4)
Total	$	630	$	(1,674)	$	(1,044)

____________

(a)Electricity purchase and sales contracts include (i) power and Heat Rate positions in ERCOT, PJM, ISO-NE, NYISO, MISO and CAISO regions, (ii) Options consist of physical electricity options, spread options and natural gas options, (iii) Forward purchase contracts (swaps and options) used to hedge electricity price differences between settlement points are referred to as congestion revenue rights (CRRs) in ERCOT and financial transmission rights (FTRs) in PJM, ISO-NE, NYISO and MISO regions, and (iv) Natural gas contracts include swaps and forward contracts.

(b)The range of the inputs may be influenced by factors such as time of day, delivery period, season and location. The average represents the arithmetic average of the underlying inputs and is not weighted by the related fair value or notional amount.

(c)Primarily based on the historical range of forward average hourly ERCOT North Hub and ERCOT South and West Zone prices.

(d)Primarily based on historical forward ERCOT and PJM power prices and ERCOT Heat Rate variability.

(e)Primarily based on the historical forward correlation and volatility within ERCOT and PJM.

(f)While we use the market approach, there is insufficient market data for the inputs to the valuation to consider the valuation liquid.

(g)Primarily based on the historical price differences between settlement points within ERCOT hubs and load zones.

(h)Primarily based on the historical forward PJM and Northeast natural gas basis prices and fixed prices.

(i)Primarily based on the historical forward natural gas fixed prices.

(j)Other includes contracts for coal and environmental allowances.

Schedule of Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation

The following table presents the changes in fair value of the Level 3 assets and liabilities:

	Year Ended December 31,
	2024		2023		2022
	(in millions)
Net liability balance at beginning of period	$	(1,044)	$	(1,219)	$	(360)
Total unrealized valuation gains (losses)	(175)		(765)		(1,382)
Purchases, issuances and settlements (a):
Purchases	266		222		185
Issuances	(26)		(30)		(62)
Settlements	137		136		345
Transfers into Level 3 (b)	(15)		(48)		(30)
Transfers out of Level 3 (b)	118		660		85
Net liabilities assumed in connection with the Energy Harbor Merger	(13)		—		—
Net change	292		175		(859)
Net liability balance at end of period	$	(752)	$	(1,044)	$	(1,219)
Unrealized valuation (losses) relating to instruments held at end of period	$	(416)	$	(676)	$	(977)

____________

(a)Settlements reflect reversals of unrealized mark-to-market valuations previously recognized in net income. Purchases and issuances reflect option premiums paid or received, including CRRs and FTRs.

(b)Includes transfers due to changes in the observability of significant inputs. All Level 3 transfers during the periods presented are in and out of Level 2. For the year ended December 31, 2024, transfers into Level 3 primarily consist of power derivatives where forward pricing inputs have become unobservable and transfers out of Level 3 primarily consist of power and natural gas derivatives where forward pricing inputs have become observable. For the year ended December 31, 2023, transfers into Level 3 primarily consist of power derivatives where forward pricing inputs have become unobservable and transfers out of Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become observable. For the year ended December 31, 2022, transfers into Level 3 primarily consist of power and coal derivatives where forward pricing inputs have become unobservable and transfers out of Level 3 primarily consist of power, natural gas, and coal derivatives where forward pricing inputs have become observable.

Schedule of Fair Value of Debt

		December 31, 2024				December 31, 2023
Instrument	Fair Value Hierarchy	Carrying Amount		Fair Value		Carrying Amount		Fair Value
		(in millions)
Long-term debt under the Vistra Operations Credit Facilities	Level 2	$	2,435	$	2,478	$	2,456	$	2,500
BCOP Credit Facilities Tax Credit Bridge Loan	Level 3	344		367		—		—
Vistra Zero Term Loan B Facility	Level 2	685		697		—		—
Vistra Operations Senior Notes	Level 2	12,366		12,428		11,881		11,752
Energy Harbor Revenue Bonds	Level 2	414		431		—		—
Equipment Financing Agreements	Level 3	54		53		65		62
Forward Repurchase Obligation	Level 3	1,335		1,335		—		—