MP Materials (MP) 10-Q 5 May 23 2023 Q1 Quarterly report Financial data

COVER

COVER - shares	3 Months Ended
	Mar. 31, 2023	May 01, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-39277
Entity Registrant Name	MP Materials Corp. / DE
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4465489
Entity Address, Address Line One	1700 S. Pavilion Center Drive, Suite 800
Entity Address, City or Town	Las Vegas
Entity Address, State or Province	NV
Entity Address, Postal Zip Code	89135
City Area Code	702
Local Phone Number	844-6111
Title of 12(b) Security	Common Stock, par value of $0.0001 per share
Trading Symbol	MP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		177,620,849
Amendment Flag	false
Entity Central Index Key	0001801368
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 651,215	$ 136,627
Short-term investments	517,831	1,045,718
Total cash, cash equivalents and short-term investments	1,169,046	1,182,345
Accounts receivable (including related party), net of allowance for credit losses of $0 and $0, respectively	21,245	32,856
Inventories	61,804	57,554
Income taxes receivable	1,727	2,201
Prepaid expenses and other current assets	13,566	18,872
Total current assets	1,267,388	1,293,828
Non-current assets
Property, plant and equipment, net	1,002,240	935,743
Non-current inventories	6,844	5,744
Other non-current assets	4,630	2,472
Total non-current assets	1,013,714	943,959
Total assets	2,281,102	2,237,787
Current liabilities
Accounts payable, construction payables and accrued liabilities	68,574	72,265
Income taxes payable	21,161	21,163
Other current liabilities	4,139	4,053
Total current liabilities	93,874	97,481
Non-current liabilities
Asset retirement obligations	5,351	5,295
Environmental obligations	16,571	16,580
Long-term debt, net	679,326	678,444
Deferred income taxes	129,711	122,353
Other non-current liabilities	4,464	5,000
Total non-current liabilities	835,423	827,672
Total liabilities	929,297	925,153
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock ($0.0001 par value, 50,000,000 shares authorized, none issued and outstanding in either period)	0	0
Common stock ($0.0001 par value, 450,000,000 shares authorized, 177,619,805 and 177,706,608 shares issued and outstanding, as of March 31, 2023, and December 31, 2022, respectively)	17	18
Additional paid-in capital	952,791	951,008
Retained earnings	398,866	361,419
Accumulated other comprehensive income	131	189
Total stockholders’ equity	1,351,805	1,312,634
Total liabilities and stockholders’ equity	$ 2,281,102	$ 2,237,787

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Allowance for credit losses	$ 0	$ 0
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (shares)	50,000,000	50,000,000
Preferred stock, issued (shares)	0	0
Preferred shares, outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (shares)	450,000,000	450,000,000
Common stock, outstanding (shares)	177,619,805	177,706,608
Common stock, issued (shares)	177,619,805	177,706,608

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total revenue	$ 95,700	$ 166,258
Operating costs and expenses:
Cost of sales (including related party)(excluding depreciation, depletion and amortization)	24,216	23,173
Selling, general and administrative	19,403	20,308
Advanced projects, start-up, development and other	8,280	1,818
Depreciation, depletion and amortization	8,122	5,260
Accretion of asset retirement and environmental obligations	227	418
Loss on sale or disposal of long-lived assets, net	2,490	257
Total operating costs and expenses	62,738	51,234
Operating income	32,962	115,024
Interest expense, net	(1,359)	(1,905)
Other income, net	13,693	194
Income before income taxes	45,296	113,313
Income tax expense	(7,849)	(27,762)
Net income	$ 37,447	$ 85,551
Earnings per share:
Basic (in USD per share)	$ 0.21	$ 0.49
Diluted (in USD per share)	$ 0.20	$ 0.45
Weighted-average shares outstanding:
Basic (in shares)	176,881,723	176,355,566
Diluted (in shares)	193,613,539	193,490,330
Product sales (including related party)
Total revenue	$ 95,666	$ 161,755
Other sales (including related party)
Total revenue	$ 34	$ 4,503

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 37,447	$ 85,551
Other comprehensive loss, net of tax:
Unrealized losses on available-for-sale securities	(58)	0
Total comprehensive income	$ 37,389	$ 85,551

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning balance (in shares) at Dec. 31, 2021		0	177,816,554
Beginning balance at Dec. 31, 2021	$ 1,008,732	$ 0	$ 18	$ 936,299	$ 72,415	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			46,882
Stock-based compensation	10,179			10,179
Shares used to settle payroll tax withholding (in shares)			(337,429)
Shares used to settle payroll tax withholding	(14,094)			(14,094)
Net income	85,551				85,551
Unrealized losses on available-for-sale securities	0
Ending balance (in shares) at Mar. 31, 2022		0	177,526,007
Ending balance at Mar. 31, 2022	1,090,368	$ 0	$ 18	932,384	157,966	0
Beginning balance (in shares) at Dec. 31, 2022		0	177,706,608
Beginning balance at Dec. 31, 2022	1,312,634	$ 0	$ 18	951,008	361,419	189
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			98,418
Stock-based compensation	7,758			7,758
Shares used to settle payroll tax withholding (in shares)			(185,221)
Shares used to settle payroll tax withholding	(5,976)		$ (1)	(5,975)
Net income	37,447				37,447
Unrealized losses on available-for-sale securities	(58)					(58)
Ending balance (in shares) at Mar. 31, 2023		0	177,619,805
Ending balance at Mar. 31, 2023	$ 1,351,805	$ 0	$ 17	$ 952,791	$ 398,866	$ 131

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities:
Net income	$ 37,447	$ 85,551
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	8,122	5,260
Accretion of asset retirement and environmental obligations	227	418
Accretion of discount on short-term investments	(8,842)	0
Loss (gain) on sale or disposal of long-lived assets, net	(5)	257
Stock-based compensation expense	7,013	9,773
Accretion of debt discount and amortization of debt issuance costs	882	1,394
Revenue recognized in exchange for debt principal reduction	0	(13,566)
Deferred income taxes	7,377	23,479
Decrease (increase) in operating assets:
Accounts receivable (including related party)	11,611	13,901
Inventories	(5,024)	(927)
Income taxes receivable	474	0
Prepaid expenses, other current and non-current assets	(351)	694
Increase (decrease) in operating liabilities:
Accounts payable and accrued liabilities	(3,586)	(7,176)
Income taxes payable	(2)	1,783
Other current and non-current liabilities	148	130
Net cash provided by operating activities	55,491	120,971
Investing activities:
Additions to property, plant and equipment	(74,462)	(54,932)
Purchases of short-term investments	(320,884)	0
Proceeds from sales of short-term investments	447,227	0
Proceeds from maturities of short-term investments	410,307	0
Proceeds from government awards used for construction	0	5,130
Net cash provided by (used in) investing activities	462,188	(49,802)
Financing activities:
Principal payments on debt obligations and finance leases	(846)	(3,817)
Tax withholding on stock-based awards	(5,976)	(14,094)
Net cash used in financing activities	(6,822)	(17,911)
Net change in cash, cash equivalents and restricted cash	510,857	53,258
Cash, cash equivalents and restricted cash beginning balance	143,509	1,181,157
Cash, cash equivalents and restricted cash ending balance	654,366	1,234,415
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	651,215	1,233,300
Restricted cash, current	2,552	587
Restricted cash, non-current	599	528
Total cash, cash equivalents and restricted cash	$ 654,366	$ 1,234,415

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Description of Business: MP Materials Corp., including its subsidiaries (the “Company” or “MP Materials”), is the largest producer of rare earth materials in the Western Hemisphere. The Company, which is headquartered in Las Vegas, Nevada, owns and operates the Mountain Pass Rare Earth Mine and Processing Facility (“Mountain Pass”), the only rare earth mining and processing site of scale in North America. MP Materials currently produces a rare earth concentrate that is principally sold pursuant to the Offtake Agreement to Shenghe (as such terms are defined in Note 13, “Related-Party Transactions,” ), a related party of the Company, that, in turn, typically sells that product to refiners in China. These refiners separate the constituent rare earth elements contained in the Company’s concentrate and sell the separated products to their customers. Upon completing commissioning of the Stage II optimization project (“Stage II”), the Company anticipates producing and selling separated rare earth products, including neodymium-praseodymium (“NdPr”) oxide, to customers globally. In February 2023, the Company entered into a distributorship agreement (“Distribution Agreement”) with Sumitomo Corporation of Americas (“Sumitomo”), under which Sumitomo will serve as the exclusive distributor of NdPr oxide produced by the Company to Japanese customers. Further, in connection with the Distribution Agreement, the Company and Sumitomo intend to collaborate on the supply of rare earth metals and other products. In addition, the Company is constructing its initial rare earth metal, alloy and magnet manufacturing facility in Fort Worth, Texas (the “Fort Worth Facility”), where it anticipates manufacturing, among other products, neodymium-iron-boron (“NdFeB”) permanent magnets. Furthermore, in April 2022, the Company entered into a long-term supply agreement with General Motors Company (NYSE: GM) (“GM”) to supply U.S.-sourced and manufactured rare earth materials, alloy and finished magnets for the electric motors in more than a dozen models using GM’s Ultium Platform, with a gradual production ramp that is expected to begin in late 2023, starting with alloy. These developments are a part of the Company’s Stage III downstream expansion strategy (“Stage III”). Operating segments are defined as components of an enterprise about which separate financial information is available and evaluated regularly by the chief operating decision maker (“CODM”), or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s CODM views the Company’s operations and manages the business as one reportable segment. The cash flows and profitability of the Company’s operations are significantly affected by the market price of rare earth products. The prices of rare earth products are affected by numerous factors beyond the Company’s control. The products of the Company are sold globally, with a primary focus in the Asian market due to the refining capabilities of the region. Rare earth products are critical inputs in hundreds of existing and emerging clean-tech applications including electric vehicles and wind turbines as well as drones and defense applications. Basis of Presentation: The unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and notes required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Results of operations and cash flows for the interim periods presented herein are not necessarily indicative of the results that would be achieved during a full year of operations or in future periods. These unaudited Condensed Consolidated Financial Statements and notes thereto should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation: The unaudited Condensed Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates : The preparation of the unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the unaudited Condensed Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Accordingly, actual results may differ from those estimates. Concentration of Risk: Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents and short-term investments, and trade accounts receivable. The Company believes that its credit risk is limited because the Company’s current contracts are with companies that have a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments. As of March 31, 2023, Shenghe was the Company’s principal customer and accounted for more than 90% of product sales. Rare earth concentrate is not quoted on any major commodities market or exchange and demand for rare earth concentrate is currently constrained to a relatively limited number of refiners, a significant majority of which are based in China. Uncertainty exists as to the market price of rare earth oxide (“REO”), as evidenced by the volatility experienced in 2022 and continued into 2023 due to concerns over the global economic conditions and actual or perceived concerns over increases in the supply of rare earth products. Furthermore, while revenue is generated in the United States, Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Note 13, “Related-Party Transactions,” for additional information. The impact of the COVID-19 pandemic and its effects continue to evolve. Since the onset of the pandemic, the Company has experienced, at times, significant shipping delays due to congestion and slowdowns at U.S. and international ports caused by shortages in vessels, containers, and truckers, also disrupting the global supply chain. Despite these factors, the Company has not experienced a reduction in production or sales due to the COVID-19 pandemic. However, the COVID-19 pandemic has contributed to certain cost and schedule pressures for capital projects and may impact the reliability of transportation, particularly as the Company expects a significant increase in inbound logistics of raw materials to be consumed in Stage II operations. The Company continues to monitor the global situation, including the impacts of new and potential future variants of COVID-19, or other factors that may affect international shipping, logistics, and supply chain, or involve responses to government actions such as strikes or other disruptions. It is impossible to predict the effect and ultimate impact of the COVID-19 pandemic on the Company’s business, results of operations, production and sales volumes, or growth projects. Stock-Based Compensation: The cost of employee services received in exchange for an award of equity instruments is based on the grant-date fair value of the award. The fair value of Stock Awards (as defined in Note 10, “Stock-based Compensation,” ) is equal to the fair value of the Company’s stock on the grant date. The fair value of performance awards that include performance and/or market conditions is determined using a Monte Carlo simulation technique. The Monte Carlo simulation requires the use of inputs and assumptions such as the grant-date closing stock price, expected volatility, correlation coefficient to relevant peer groups or indices, risk-free interest rate and dividend yield. Compensation cost for Stock Awards with graded vesting schedules is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards, which results in accelerated recognition of compensation cost. Compensation cost for performance awards with cliff vesting schedules is recognized on a straight-line basis over the requisite service period. Compensation cost is not adjusted based on the actual achievement of the market-based performance goals. The Company accounts for forfeitures in the period in which they occur based on actual forfeitures. See also Note 10, “Stock-based Compensation.” Recently Issued Accounting Pronouncements: During the three months ended March 31, 2023, there were no accounting pronouncements adopted by the Company that had a material impact on the Company's unaudited Condensed Consolidated Financial Statements. Additionally, as of March 31, 2023, there were no accounting pronouncements pending adoption that are expected to have a material impact on the Company's unaudited Condensed Consolidated Financial Statements. Reclassifications: Certain amounts in prior periods have been reclassified to conform to the current year presentation.

CASH, CASH EQUIVALENTS AND INVE

CASH, CASH EQUIVALENTS AND INVESTMENTS	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
CASH, CASH EQUIVALENTS AND INVESTMENTS	CASH, CASH EQUIVALENTS AND INVESTMENTS The following table presents the Company’s cash, cash equivalents and short-term investments: March 31, 2023 December 31, 2022 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 24,572 $ — $ — $ 24,572 $ 7,373 $ — $ — $ 7,373 Cash equivalents: Money market funds 626,643 — — 626,643 64,855 — — 64,855 U.S. agency securities — — — — 63,605 1 (2) 63,604 U.S. Treasury securities — — — — 795 — — 795 Total cash equivalents 626,643 — — 626,643 129,255 1 (2) 129,254 Total cash and equivalents 651,215 — — 651,215 136,628 1 (2) 136,627 Short-term investments: U.S. agency securities 482,012 201 (12) 482,201 979,878 361 (17) 980,222 U.S. Treasury securities 35,644 — (14) 35,630 65,586 1 (91) 65,496 Total short-term investments 517,656 201 (26) 517,831 1,045,464 362 (108) 1,045,718 Total cash, cash equivalents and short-term investments $ 1,168,871 $ 201 $ (26) $ 1,169,046 $ 1,182,092 $ 363 $ (110) $ 1,182,345 The Company does not intend to sell, nor is it more likely than not that the Company will be required to sell, any investments in unrealized loss positions before recovery of their amortized cost basis. The Company did not recognize any credit losses related to its available-for-sale investments during the three months ended March 31, 2023. The unrealized losses on the Company’s available-for-sale investments were primarily due to unfavorable changes in interest rates subsequent to initial purchase. None of the available-for-sale investments held as of March 31, 2023, were in a continuous unrealized loss position for greater than 12 months and the unrealized losses and the related risk of expected credit losses were not material. The Company recognized $0.5 million of gross realized gains and $0.1 million of gross realized losses during the three months ended March 31, 2023. Additionally, the Company recognized $13.3 million of interest and investment income on its available-for-sale securities and other money market funds for the three months ended March 31, 2023. These amounts are included in “Other income, net” within the Company’s unaudited Condensed Consolidated Statements of Operations. As of March 31, 2023, the fair values of available-for-sale investments, by remaining contractual maturity, were as follows: (in thousands) Due within one year $ 494,930 Due after one year through two years 22,901 Total $ 517,831

INVENTORIES

INVENTORIES	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES The Company’s inventories consisted of the following: March 31, 2023 December 31, 2022 (in thousands) Materials and supplies (1) $ 31,402 $ 28,590 In-process 28,929 27,212 Finished goods 1,473 1,752 Total current inventories 61,804 57,554 Add: Non-current portion (2) 6,844 5,744 Total inventories $ 68,648 $ 63,298 (1) Includes materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing facility as a part of Stage III. (2) Represents stockpiled ore that is not expected to be processed within the next 12 months.

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT The Company’s property, plant and equipment consisted of the following: March 31, 2023 December 31, 2022 (in thousands) Land and land improvements $ 16,112 $ 16,102 Buildings and building improvements 15,856 15,111 Machinery and equipment 275,541 186,388 Assets under construction 323,444 338,482 Mineral rights 438,395 438,395 Property, plant and equipment, gross 1,069,348 994,478 Less: Accumulated depreciation and depletion (67,108) (58,735) Property, plant and equipment, net $ 1,002,240 $ 935,743 Additions to Property, Plant and Equipment: The Company capitalized expenditures related to property, plant and equipment of $74.3 million and $68.0 million for the three months ended March 31, 2023 and 2022, respectively, including amounts not yet paid (see Note 14, “Supplemental Cash Flow Information” ). The capitalized expenditures related to machinery, equipment, and assets under construction to support the Company’s Stage II optimization project, and assets under construction for its rare earth metal, alloy and magnet manufacturing facility as a part of Stage III. Additionally, t he capitalized expenditures for the three months ended March 31, 2022, included the purchase of approximately 18 acres of land in Fort Worth, Texas . Placement of Certain Stage II Assets into Service: At the end of the first quarter of 2023, the Company transferred certain of its assets totaling $86.4 million and pertaining to its Stage II optimization project from assets under construction to buildings, machinery and equipment, with $85.7 million relating to machinery and equipment. Government Awards: In November 2020, the Company was awarded a Defense Production Act Title III technology investment agreement (“TIA”) from the Department of Defense (“DOD”) to establish domestic processing for separated light rare earth elements in the amount of $9.6 million. During the three months ended March 31, 2023 and 2022, pursuant to the TIA, the Company had received zero and $5.1 million, respectively, in reimbursements from the DOD. As of March 31, 2023, the Company is entitled to receive an additional $0.1 million from the DOD under the TIA. In February 2022, the Company was awarded a $35.0 million contract by the DOD’s Office of Industrial Base Analysis and Sustainment program to design and build a facility to process heavy rare earth elements (“HREE”) at Mountain Pass (the “HREE Production Project Agreement”). As of March 31, 2023, the Company has not yet received any funds from the DOD under the HREE Production Project Agreement. The Company’s depreciation and depletion expense were as follows: For the three months ended March 31, (in thousands) 2023 2022 Depreciation expense $ 5,245 $ 2,101 Depletion expense $ 2,800 $ 3,069 The Company recognized $2.5 million of demolition costs for the three months ended March 31, 2023, which are included in “Loss on sale or disposal of long-lived assets, net” within the Company’s unaudited Condensed Consolidated Statements of Operations, incurred in connection with demolishing and removing certain old facilities from the Mountain Pass site that have not been used in the Company’s operations. There were no impairments recognized for the three months ended March 31, 2023 and 2022.

DEBT OBLIGATIONS

DEBT OBLIGATIONS	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
DEBT OBLIGATIONS	DEBT OBLIGATIONS The Company’s long-term debt was as follows: March 31, 2023 December 31, 2022 (in thousands) Long-term debt Convertible Notes due 2026 $ 690,000 $ 690,000 Less: Unamortized debt issuance costs (10,674) (11,556) Long-term debt, net $ 679,326 $ 678,444 Convertible Notes In March 2021, the Company issued $690.0 million aggregate principal amount of 0.25% unsecured green convertible senior notes that mature, unless earlier converted, redeemed or repurchased, on April 1, 2026 (the “Convertible Notes”), at a price of par. Interest on the Convertible Notes is payable on April 1 st and October 1 st of each year, beginning on October 1, 2021. The Convertible Notes may, at the Company’s election, be settled in cash, shares of common stock of the Company, or a combination thereof. The Company has the option to redeem the Convertible Notes, in whole or in part, beginning on April 5, 2024. The Convertible Notes are convertible into shares of the Company’s common stock at an initial conversion price of $44.28 per share, or 22.5861 shares, per $1,000 principal amount of notes, subject to adjustment upon the occurrence of certain corporate events. However, in no event will the conversion price exceed 28.5714 shares of common stock per $1,000 principal amount of notes. As of March 31, 2023, based on the conversion price, the maximum number of shares that could be issued to satisfy the conversion feature of the Convertible Notes was 19,714,266. The Convertible Notes’ if-converted value did not exceed its principal amount as of March 31, 2023. Interest expense related to the Convertible Notes was as follows: For the three months ended March 31, (in thousands) 2023 2022 Coupon interest $ 431 $ 431 Amortization of debt issuance costs 882 877 Convertible Notes interest expense $ 1,313 $ 1,308 The debt issuance costs are being amortized to interest expense over the term of the Convertible Notes at an effective interest rate of 0.51%. The remaining term of the Convertible Notes was 3.0 years as of March 31, 2023. Equipment Notes The Company has entered into several financing agreements for the purchase of equipment, including trucks, tractors, loaders, graders, and various other machinery. The Company’s equipment notes, which are secured by the purchased equipment, have terms of between 4 to 5 years and interest rates of between 0.0% and 6.5% per annum. The current and non-current portions of the equipment notes, which are included within the unaudited Condensed Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows: March 31, 2023 December 31, 2022 (in thousands) Equipment notes Current $ 2,327 $ 2,392 Non-current 4,187 4,743 $ 6,514 $ 7,135 As of March 31, 2023, none of the agreements or indentures governing the Company’s indebtedness contain financial covenants.

ASSET RETIREMENT AND ENVIRONMEN

ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS	3 Months Ended
	Mar. 31, 2023
Asset Retirement Obligation Disclosure [Abstract]
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS	ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS Asset Retirement Obligations The Company estimates asset retirement obligations based on the requirements to reclaim certain land areas associated with mineral extraction activities and certain related facilities at Mountain Pass. Minor reclamation activities related to discrete portions of the Company’s operations are ongoing. As of March 31, 2023, the Company estimated a significant portion of the cash outflows for major reclamation activities including the retirement of Mountain Pass will be incurred beginning in 2056 and 2057. As of March 31, 2023, the credit-adjusted risk-free rate ranged between 6.5% and 12.0% depending on the timing of expected settlement and when the increment was recognized. There were no significant increments or decrements for the three months ended March 31, 2023 and 2022. The balance as of both March 31, 2023, and December 31, 2022, included current portions of $0.2 million. The total estimated future undiscounted cash flows required to satisfy the Company’s asset retirement obligations were $50.3 million and $50.4 million as of March 31, 2023, and December 31, 2022, respectively. Environmental Obligations The Company has certain environmental remediation liabilities related to the monitoring of groundwater contamination. The Company engaged an environmental consultant to develop a remediation plan and remediation cost projections based upon that plan. Utilizing the remediation plan developed by the environmental consultant, the Company developed an estimate of future cash payments for the remediation plan. As of March 31, 2023, the Company estimated the cash outflows related to these environmental activities will be incurred annually over the next 25 years. The Company’s environmental remediation liabilities are measured at the expected value of future cash outflows discounted to their present value using a discount rate of 2.93%. There were no significant changes in the estimated remaining remediation costs for the three months ended March 31, 2023 and 2022. The total estimated aggregate undiscounted cost of $27.0 million and $27.2 million as of March 31, 2023, and December 31, 2022, respectively, principally related to water monitoring activities required by state and local agencies. Based on the Company’s estimate of the cost and timing and the assumption that payments are considered to be fixed and reliably determinable, the Company has discounted the liability. The balance as of both March 31, 2023, and December 31, 2022, included current portions of $0.5 million. Financial Assurances The Company is required to provide the applicable government agencies with financial assurances relating to the closure and reclamation obligations. As of both March 31, 2023, and December 31, 2022, the Company had financial assurance requirements of $43.5 million, which were satisfied with surety bonds placed with California state and regional agencies.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2023
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company calculates the provision for income taxes during interim reporting periods by applying an estimate of the annual effective tax rate to its year-to-date pretax book income or loss. The tax effects of discrete items, including but not limited to, excess tax benefits associated with stock-based compensation, valuation allowance adjustments based on new evidence, and enactment of tax laws, are reported in the interim period in which they occur. The effective tax rate (income taxes as a percentage of income or loss before income taxes) including discrete items was 17.3% and 24.5% for the three months ended March 31, 2023 and 2022, respectively. The Company’s effective income tax rate can vary from period to period depending on, among other factors, percentage depletion, executive compensation deduction limitations, the Section 45X Advanced Manufacturing Production Credit, and changes to its valuation allowance against deferred tax assets. Certain of these and other factors, including the Company’s history and projections of pretax earnings, are considered in assessing its ability to realize its net deferred tax assets. On August 16, 2022, the U.S. government enacted the Inflation Reduction Act of 2022 which, among other things, implements a 15% minimum tax on book income of certain large corporations, a 1% excise tax on net stock repurchases, and provides several tax incentives to promote clean energy for tax years beginning after December 31, 2022. The Company does not expect the minimum tax or excise tax to have a material impact on the unaudited Condensed Consolidated Financial

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Mar. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Litigation: The Company may become party to lawsuits, administrative proceedings and government investigations, including environmental, regulatory, and other matters, in the ordinary course of business. Large, and sometimes unspecified, damages or penalties may be sought in some matters, and certain matters may require years to resolve. The Company is not aware of any pending or threatened litigation that would have a material adverse effect on its unaudited Condensed Consolidated Financial Statements.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2020 Incentive Plan: In November 2020, the Company’s stockholders approved the MP Materials Corp. 2020 Stock Incentive Plan (the “2020 Incentive Plan”), which permits the Company to issue stock options (incentive and/or non-qualified); stock appreciation rights (“SARs”); restricted stock, restricted stock units (“RSUs”) and other stock awards (collectively, the “Stock Awards”); and performance awards, which vest contingent upon the attainment of either or a combination of market- or performance-based goals. As of March 31, 2023, the Company has not issued any stock options or SARs and there were 6,326,026 shares available for future grants under the 2020 Incentive Plan. Market-Based PSUs: In February 2023, pursuant to the 2020 Incentive Plan, the Company’s Compensation Committee of the Board of Directors adopted a performance share plan (the “2023 Performance Share Plan”). Pursuant to the 2023 Performance Share Plan, for the three months ended March 31, 2023, the Company granted 62,709 of market-based performance stock units (“PSUs”) at target, all of which cliff vest after a requisite performance and service period of three years. The PSUs have the potential to be earned at between 0% and 200% of the number of awards granted depending on the level of growth of the Company’s total shareholder return (“TSR”) as compared to the TSR of the S&P 400 Index and the S&P 400 Materials Group over the performance period. The fair value of the market-based PSUs was determined using a Monte Carlo simulation technique. Stock-Based Compensation: The Company’s stock-based compensation was recorded as follows: For the three months ended March 31, (in thousands) 2023 2022 Cost of sales $ 1,122 $ 715 Selling, general and administrative 5,774 8,968 Advanced projects, start-up, development and other 117 90 Total stock-based compensation expense $ 7,013 $ 9,773 Stock-based compensation capitalized to property, plant and equipment, net $ 745 $ 406

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Accounting Standards Codification (“ASC”) Topic 820, “Fair Value Measurements and Disclosures” (“ASC 820”), establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 Quoted prices in markets that are not active, quoted prices for similar assets or liabilities in active markets, quoted prices or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability and model-based valuation techniques (e.g., the Black-Scholes model) for which all significant inputs are observable in active markets. Level 3 Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity). The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of assets and liabilities and their placement within the fair value hierarchy. The following methods and assumptions are used to estimate the fair value of each class of financial instruments for which it is practicable to estimate. The fair value of the Company’s accounts receivable, accounts payable, short-term debt and accrued liabilities approximates the carrying amounts because of the immediate or short-term maturity of these financial instruments. Cash, Cash Equivalents and Restricted Cash The Company’s cash, cash equivalents and restricted cash are classified within Level 1 of the fair value hierarchy. The carrying amounts reported in the unaudited Condensed Consolidated Balance Sheets approximate the fair value of cash, cash equivalents and restricted cash due to the short-term nature of these assets. Short-term Investments The fair value of the Company’s short-term investments, which are classified as available-for-sale securities, is estimated based on quoted prices in active markets and is classified as a Level 1 measurement. Convertible Notes The fair value of the Company’s Convertible Notes is estimated based on quoted prices in active markets and is classified as a Level 1 measurement. Equipment Notes The Company’s equipment notes are classified within Level 2 of the fair value hierarchy because there are inputs that are directly observable for substantially the full term of the liability. Model-based valuation techniques for which all significant inputs are observable in active markets were used to calculate the fair values of liabilities classified within Level 2 of the fair value hierarchy. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: March 31, 2023 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 651,215 $ 651,215 $ 651,215 $ — $ — Short-term investments $ 517,831 $ 517,831 $ 517,831 $ — $ — Restricted cash $ 3,151 $ 3,151 $ 3,151 $ — $ — Financial liabilities: Convertible Notes $ 679,326 $ 652,485 $ 652,485 $ — $ — Equipment notes $ 6,514 $ 6,350 $ — $ 6,350 $ — December 31, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 136,627 $ 136,627 $ 136,627 $ — $ — Short-term investments $ 1,045,718 $ 1,045,718 $ 1,045,718 $ — $ — Restricted cash $ 6,882 $ 6,882 $ 6,882 $ — $ — Financial liabilities: Convertible Notes $ 678,444 $ 610,650 $ 610,650 $ — $ — Equipment notes $ 7,135 $ 6,807 $ — $ 6,807 $ —

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic earnings per share (“EPS”) is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income by the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method or the if-converted method, as applicable. The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS: For the three months ended March 31, 2023 2022 Weighted-average shares outstanding, basic 176,881,723 176,355,566 Assumed conversion of Convertible Notes 15,584,409 15,584,409 Assumed conversion of restricted stock 723,145 1,148,539 Assumed conversion of RSUs 424,262 401,816 Weighted-average shares outstanding, diluted 193,613,539 193,490,330 The following table presents the calculation of basic and diluted EPS for the Company’s common stock: For the three months ended March 31, (in thousands, except share and per share data) 2023 2022 Calculation of basic EPS: Net income $ 37,447 $ 85,551 Weighted-average shares outstanding, basic 176,881,723 176,355,566 Basic EPS $ 0.21 $ 0.49 Calculation of diluted EPS: Net income $ 37,447 $ 85,551 Interest expense, net of tax (1) : Convertible Notes 1,086 988 Diluted income $ 38,533 $ 86,539 Weighted-average shares outstanding, diluted 193,613,539 193,490,330 Diluted EPS $ 0.20 $ 0.45 (1) The three months ended March 31, 2023 and 2022, were tax-effected at a rate of 17.3% and 24.5%, respectively.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2023
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED-PARTY TRANSACTIONS Offtake Agreement: In March 2022, the Company entered into an offtake agreement (the “Offtake Agreement”) with Shenghe Resources (Singapore) International Trading Pte. Ltd. (“Shenghe”), a majority-owned subsidiary of Leshan Shenghe Rare Earth Co., Ltd. (“Leshan Shenghe”) whose ultimate parent is Shenghe Resources Holding Co., Ltd., a leading global rare earth company listed on the Shanghai Stock Exchange. The Offtake Agreement became effective upon the termination of the A&R Offtake Agreement (as discussed and defined below). The initial term of the Offtake Agreement is two years, with the option to extend the term at the Company’s discretion for an additional one-year period. Pursuant to the Offtake Agreement, and subject to certain exclusions, Shenghe is obligated to purchase on a “take or pay” basis the rare earth concentrate produced by the Company as the exclusive distributor in China, with certain exceptions for the Company’s direct sales globally. In addition, at the discretion of the Company, Shenghe may be required to purchase on a “take or pay” basis certain non-concentrate rare earth products, although the Company may sell all non-concentrate rare earth products in its sole discretion to customers or end users in any jurisdiction. Under the Offtake Agreement, Shenghe will be paid a variable commission on net proceeds to the Company. The sales price of rare earth concentrate sold to Shenghe is based on an agreed-upon price per metric ton, subject to certain quality adjustments depending on the measured characteristics of the product, with an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. The sales price and other terms applicable to a quantity of offtake products are set forth in monthly purchase agreements between the Company and Shenghe. Tolling Agreement with VREX: In March 2023, the Company entered into a tolling agreement with Vietnam Rare Earth Company Limited (“VREX”), a majority-owned subsidiary of Shenghe, which owns and operates a metal processing plant and related facilities in Vietnam (the “Tolling Agreement”). Pursuant to the Tolling Agreement, the Company would deliver NdPr oxide to VREX which VREX would then process into NdPr metal for delivery to the Company’s customers globally. During the term of the Tolling Agreement, the Company will pay VREX a processing fee per unit of rare earth metal produced. The Company will maintain title to the products and directly enter into sales agreements for the produced NdPr metal. The initial term of the Tolling Agreement is three years and may be renewed for additional three-year terms. As of March 31, 2023, there have not yet been any transactions as contemplated under the Tolling Agreement. Product Sales and Cost of Sales: Product sales from sales agreements with Shenghe for rare earth products were $89.1 million and $155.0 million for the three months ended March 31, 2023 and 2022, respectively. During the three months ended March 31, 2022, the Company also entered into sales agreements with Shenghe for non-concentrate products, including certain stockpiles of rare earth fluoride. These sales, which are included in the unaudited Condensed Consolidated Statements of Operations in “Other sales (including related party),” were $4.1 million for the three months ended March 31, 2022. Cost of sales, which includes shipping and freight, related to these agreements with Shenghe was $22.7 million and $22.6 million for the three months ended March 31, 2023 and 2022, respectively. Purchases of Materials and Supplies: The Company purchases certain reagent products (generally produced by an unrelated third-party manufacturer) used in the flotation process as well as other materials from Shenghe in the ordinary course of business. Total purchases were $0.9 million and $1.2 million for the three months ended March 31, 2023 and 2022, respectively. Accounts Receivable: As of March 31, 2023, and December 31, 2022, $18.8 million and $29.8 million, respectively, of the accounts receivable as stated in the unaudited Condensed Consolidated Balance Sheets, were receivable from and pertained to sales made to Shenghe in the ordinary course of business.

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Mar. 31, 2023
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information and non-cash investing and financing activities were as follows: For the three months ended March 31, (in thousands) 2023 2022 Supplemental cash flow information: Cash paid for interest $ 105 $ 83 Cash payments related to income taxes $ — $ 2,500 Change in construction payables $ (130) $ 13,096 Supplemental non-cash investing and financing activities: Revenue recognized in exchange for debt principal reduction $ — $ 13,566

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Basis of Presentation	The unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and notes required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.Results of operations and cash flows for the interim periods presented herein are not necessarily indicative of the results that would be achieved during a full year of operations or in future periods. These unaudited Condensed Consolidated Financial Statements and notes thereto should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022.
Principles of Consolidation	The unaudited Condensed Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	The preparation of the unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the unaudited Condensed Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Accordingly, actual results may differ from those estimates.
Concentration of Risk	Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents and short-term investments, and trade accounts receivable. The Company believes that its credit risk is limited because the Company’s current contracts are with companies that have a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments. As of March 31, 2023, Shenghe was the Company’s principal customer and accounted for more than 90% of product sales. Rare earth concentrate is not quoted on any major commodities market or exchange and demand for rare earth concentrate is currently constrained to a relatively limited number of refiners, a significant majority of which are based in China. Uncertainty exists as to the market price of rare earth oxide (“REO”), as evidenced by the volatility experienced in 2022 and continued into 2023 due to concerns over the global economic conditions and actual or perceived concerns over increases in the supply of rare earth products. Furthermore, while revenue is generated in the United States, Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Note 13, “Related-Party Transactions,” for additional information. The impact of the COVID-19 pandemic and its effects continue to evolve. Since the onset of the pandemic, the Company has experienced, at times, significant shipping delays due to congestion and slowdowns at U.S. and international ports caused by shortages in vessels, containers, and truckers, also disrupting the global supply chain. Despite these factors, the Company has not experienced a reduction in production or sales due to the COVID-19 pandemic. However, the COVID-19 pandemic has contributed to certain cost and schedule pressures for capital projects and may impact the reliability of transportation, particularly as the Company expects a significant increase in inbound logistics of raw materials to be consumed in Stage II operations. The Company continues to monitor the global situation, including the impacts of new and potential future variants of COVID-19, or other factors that may affect international shipping, logistics, and supply chain, or involve responses to government actions such as strikes or other disruptions. It is impossible to predict the effect and ultimate impact of the COVID-19 pandemic on the Company’s business, results of operations, production and sales volumes, or growth projects.
Stock-Based Compensation	The cost of employee services received in exchange for an award of equity instruments is based on the grant-date fair value of the award. The fair value of Stock Awards (as defined in Note 10, “Stock-based Compensation,” ) is equal to the fair value of the Company’s stock on the grant date. The fair value of performance awards that include performance and/or market conditions is determined using a Monte Carlo simulation technique. The Monte Carlo simulation requires the use of inputs and assumptions such as the grant-date closing stock price, expected volatility, correlation coefficient to relevant peer groups or indices, risk-free interest rate and dividend yield. Compensation cost for Stock Awards with graded vesting schedules is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards, which results in accelerated recognition of compensation cost. Compensation cost for performance awards with cliff vesting schedules is recognized on a straight-line basis over the requisite service period. Compensation cost is not adjusted based on the actual achievement of the market-based performance goals. The Company accounts for forfeitures in the period in which they occur based on actual forfeitures. See also Note 10, “Stock-based Compensation.”
Recently Issued Accounting Pronouncements	During the three months ended March 31, 2023, there were no accounting pronouncements adopted by the Company that had a material impact on the Company's unaudited Condensed Consolidated Financial Statements. Additionally, as of March 31, 2023, there were no accounting pronouncements pending adoption that are expected to have a material impact on the Company's unaudited Condensed Consolidated Financial Statements.
Reclassifications	Certain amounts in prior periods have been reclassified to conform to the current year presentation.

CASH, CASH EQUIVALENTS AND IN_2

CASH, CASH EQUIVALENTS AND INVESTMENTS (Tables)	3 Months Ended
	Mar. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-Sale	The following table presents the Company’s cash, cash equivalents and short-term investments: March 31, 2023 December 31, 2022 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 24,572 $ — $ — $ 24,572 $ 7,373 $ — $ — $ 7,373 Cash equivalents: Money market funds 626,643 — — 626,643 64,855 — — 64,855 U.S. agency securities — — — — 63,605 1 (2) 63,604 U.S. Treasury securities — — — — 795 — — 795 Total cash equivalents 626,643 — — 626,643 129,255 1 (2) 129,254 Total cash and equivalents 651,215 — — 651,215 136,628 1 (2) 136,627 Short-term investments: U.S. agency securities 482,012 201 (12) 482,201 979,878 361 (17) 980,222 U.S. Treasury securities 35,644 — (14) 35,630 65,586 1 (91) 65,496 Total short-term investments 517,656 201 (26) 517,831 1,045,464 362 (108) 1,045,718 Total cash, cash equivalents and short-term investments $ 1,168,871 $ 201 $ (26) $ 1,169,046 $ 1,182,092 $ 363 $ (110) $ 1,182,345
Schedule of Cash and Cash Equivalents	The following table presents the Company’s cash, cash equivalents and short-term investments: March 31, 2023 December 31, 2022 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 24,572 $ — $ — $ 24,572 $ 7,373 $ — $ — $ 7,373 Cash equivalents: Money market funds 626,643 — — 626,643 64,855 — — 64,855 U.S. agency securities — — — — 63,605 1 (2) 63,604 U.S. Treasury securities — — — — 795 — — 795 Total cash equivalents 626,643 — — 626,643 129,255 1 (2) 129,254 Total cash and equivalents 651,215 — — 651,215 136,628 1 (2) 136,627 Short-term investments: U.S. agency securities 482,012 201 (12) 482,201 979,878 361 (17) 980,222 U.S. Treasury securities 35,644 — (14) 35,630 65,586 1 (91) 65,496 Total short-term investments 517,656 201 (26) 517,831 1,045,464 362 (108) 1,045,718 Total cash, cash equivalents and short-term investments $ 1,168,871 $ 201 $ (26) $ 1,169,046 $ 1,182,092 $ 363 $ (110) $ 1,182,345
Schedule of Investments Classified by Contractual Maturity Date	As of March 31, 2023, the fair values of available-for-sale investments, by remaining contractual maturity, were as follows: (in thousands) Due within one year $ 494,930 Due after one year through two years 22,901 Total $ 517,831

INVENTORIES (Tables)

INVENTORIES (Tables)	3 Months Ended
	Mar. 31, 2023
Inventory Disclosure [Abstract]
Inventories	The Company’s inventories consisted of the following: March 31, 2023 December 31, 2022 (in thousands) Materials and supplies (1) $ 31,402 $ 28,590 In-process 28,929 27,212 Finished goods 1,473 1,752 Total current inventories 61,804 57,554 Add: Non-current portion (2) 6,844 5,744 Total inventories $ 68,648 $ 63,298 (1) Includes materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing facility as a part of Stage III. (2) Represents stockpiled ore that is not expected to be processed within the next 12 months.
Noncurrent Inventories	The Company’s inventories consisted of the following: March 31, 2023 December 31, 2022 (in thousands) Materials and supplies (1) $ 31,402 $ 28,590 In-process 28,929 27,212 Finished goods 1,473 1,752 Total current inventories 61,804 57,554 Add: Non-current portion (2) 6,844 5,744 Total inventories $ 68,648 $ 63,298 (1) Includes materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing facility as a part of Stage III. (2) Represents stockpiled ore that is not expected to be processed within the next 12 months.

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment and Depreciation and Depletion Expense	The Company’s property, plant and equipment consisted of the following: March 31, 2023 December 31, 2022 (in thousands) Land and land improvements $ 16,112 $ 16,102 Buildings and building improvements 15,856 15,111 Machinery and equipment 275,541 186,388 Assets under construction 323,444 338,482 Mineral rights 438,395 438,395 Property, plant and equipment, gross 1,069,348 994,478 Less: Accumulated depreciation and depletion (67,108) (58,735) Property, plant and equipment, net $ 1,002,240 $ 935,743 The Company’s depreciation and depletion expense were as follows: For the three months ended March 31, (in thousands) 2023 2022 Depreciation expense $ 5,245 $ 2,101 Depletion expense $ 2,800 $ 3,069

DEBT OBLIGATIONS (Tables)

DEBT OBLIGATIONS (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of long-term debt obligations	The Company’s long-term debt was as follows: March 31, 2023 December 31, 2022 (in thousands) Long-term debt Convertible Notes due 2026 $ 690,000 $ 690,000 Less: Unamortized debt issuance costs (10,674) (11,556) Long-term debt, net $ 679,326 $ 678,444 The current and non-current portions of the equipment notes, which are included within the unaudited Condensed Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows: March 31, 2023 December 31, 2022 (in thousands) Equipment notes Current $ 2,327 $ 2,392 Non-current 4,187 4,743 $ 6,514 $ 7,135
Interest expense, net	Interest expense related to the Convertible Notes was as follows: For the three months ended March 31, (in thousands) 2023 2022 Coupon interest $ 431 $ 431 Amortization of debt issuance costs 882 877 Convertible Notes interest expense $ 1,313 $ 1,308

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2023
Share-Based Payment Arrangement [Abstract]
Schedule of Stock Awards Activity	The Company’s stock-based compensation was recorded as follows: For the three months ended March 31, (in thousands) 2023 2022 Cost of sales $ 1,122 $ 715 Selling, general and administrative 5,774 8,968 Advanced projects, start-up, development and other 117 90 Total stock-based compensation expense $ 7,013 $ 9,773 Stock-based compensation capitalized to property, plant and equipment, net $ 745 $ 406

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: March 31, 2023 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 651,215 $ 651,215 $ 651,215 $ — $ — Short-term investments $ 517,831 $ 517,831 $ 517,831 $ — $ — Restricted cash $ 3,151 $ 3,151 $ 3,151 $ — $ — Financial liabilities: Convertible Notes $ 679,326 $ 652,485 $ 652,485 $ — $ — Equipment notes $ 6,514 $ 6,350 $ — $ 6,350 $ — December 31, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 136,627 $ 136,627 $ 136,627 $ — $ — Short-term investments $ 1,045,718 $ 1,045,718 $ 1,045,718 $ — $ — Restricted cash $ 6,882 $ 6,882 $ 6,882 $ — $ — Financial liabilities: Convertible Notes $ 678,444 $ 610,650 $ 610,650 $ — $ — Equipment notes $ 7,135 $ 6,807 $ — $ 6,807 $ —
Fair Value Disclosure of Asset and Liability Not Measured at Fair Value	The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: March 31, 2023 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 651,215 $ 651,215 $ 651,215 $ — $ — Short-term investments $ 517,831 $ 517,831 $ 517,831 $ — $ — Restricted cash $ 3,151 $ 3,151 $ 3,151 $ — $ — Financial liabilities: Convertible Notes $ 679,326 $ 652,485 $ 652,485 $ — $ — Equipment notes $ 6,514 $ 6,350 $ — $ 6,350 $ — December 31, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 136,627 $ 136,627 $ 136,627 $ — $ — Short-term investments $ 1,045,718 $ 1,045,718 $ 1,045,718 $ — $ — Restricted cash $ 6,882 $ 6,882 $ 6,882 $ — $ — Financial liabilities: Convertible Notes $ 678,444 $ 610,650 $ 610,650 $ — $ — Equipment notes $ 7,135 $ 6,807 $ — $ 6,807 $ —

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2023
Earnings Per Share [Abstract]
Schedule of weighted average number of shares	The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS: For the three months ended March 31, 2023 2022 Weighted-average shares outstanding, basic 176,881,723 176,355,566 Assumed conversion of Convertible Notes 15,584,409 15,584,409 Assumed conversion of restricted stock 723,145 1,148,539 Assumed conversion of RSUs 424,262 401,816 Weighted-average shares outstanding, diluted 193,613,539 193,490,330
Potentially dilutive securities	The following table presents the calculation of basic and diluted EPS for the Company’s common stock: For the three months ended March 31, (in thousands, except share and per share data) 2023 2022 Calculation of basic EPS: Net income $ 37,447 $ 85,551 Weighted-average shares outstanding, basic 176,881,723 176,355,566 Basic EPS $ 0.21 $ 0.49 Calculation of diluted EPS: Net income $ 37,447 $ 85,551 Interest expense, net of tax (1) : Convertible Notes 1,086 988 Diluted income $ 38,533 $ 86,539 Weighted-average shares outstanding, diluted 193,613,539 193,490,330 Diluted EPS $ 0.20 $ 0.45 (1) The three months ended March 31, 2023 and 2022, were tax-effected at a rate of 17.3% and 24.5%, respectively.

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2023
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Supplemental cash flow information and non-cash investing and financing activities were as follows: For the three months ended March 31, (in thousands) 2023 2022 Supplemental cash flow information: Cash paid for interest $ 105 $ 83 Cash payments related to income taxes $ — $ 2,500 Change in construction payables $ (130) $ 13,096 Supplemental non-cash investing and financing activities: Revenue recognized in exchange for debt principal reduction $ — $ 13,566

DESCRIPTION OF BUSINESS AND B_2

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Details)	3 Months Ended
	Mar. 31, 2023 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	1

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Details)	3 Months Ended
	Mar. 31, 2023
Shenghe | Product sales | Customer concentration risk | Shenghe
Concentration Risk [Line Items]
Concentration risk percentage	90%

CASH, CASH EQUIVALENTS AND IN_3

CASH, CASH EQUIVALENTS AND INVESTMENTS - Amortized Costs, Unrealized Gains and Losses, and Estimated Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Total cash and equivalents
Amortized Cost Basis	$ 651,215	$ 136,628
Unrealized Gains	0	1
Unrealized Losses	0	(2)
Estimated Fair Value	651,215	136,627
Short-term investments:
Amortized Cost Basis	517,656	1,045,464
Unrealized Gains	201	362
Unrealized Losses	(26)	(108)
Short-term investments	517,831	1,045,718
Amortized Cost Basis	1,168,871	1,182,092
Unrealized Gains	201	363
Unrealized Losses	(26)	(110)
Total cash, cash equivalents and short-term investments	1,169,046	1,182,345
Debt securities, available-for-sale, realized gain	500
Debt securities, available-for-sale, realized loss	(100)
Interest and investment income	13,300
U.S. agency securities
Short-term investments:
Amortized Cost Basis	482,012	979,878
Unrealized Gains	201	361
Unrealized Losses	(12)	(17)
Short-term investments	482,201	980,222
U.S. Treasury securities
Short-term investments:
Amortized Cost Basis	35,644	65,586
Unrealized Gains	0	1
Unrealized Losses	(14)	(91)
Short-term investments	35,630	65,496
Demand deposits
Total cash and equivalents
Amortized Cost Basis	24,572	7,373
Estimated Fair Value	24,572	7,373
Total cash equivalents
Total cash and equivalents
Amortized Cost Basis	626,643	129,255
Unrealized Gains	0	1
Unrealized Losses	0	(2)
Estimated Fair Value	626,643	129,254
Money market funds
Total cash and equivalents
Amortized Cost Basis	626,643	64,855
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	626,643	64,855
U.S. agency securities
Total cash and equivalents
Amortized Cost Basis	0	63,605
Unrealized Gains	0	1
Unrealized Losses	0	(2)
Estimated Fair Value	0	63,604
U.S. Treasury securities
Total cash and equivalents
Amortized Cost Basis	0	795
Unrealized Gains	0	0
Unrealized Losses	0	0
Estimated Fair Value	$ 0	$ 795

CASH, CASH EQUIVALENTS AND IN_4

CASH, CASH EQUIVALENTS AND INVESTMENTS - Schedule of Investments Classified by Contractual Maturity Date (Details) $ in Thousands	Mar. 31, 2023 USD ($)
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]
Due within one year	$ 494,930
Due after one year through two years	22,901
Total	$ 517,831

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Inventory Disclosure [Abstract]
Materials and supplies	$ 31,402	$ 28,590
In-process	28,929	27,212
Finished goods	1,473	1,752
Total current inventories	61,804	57,554
Add: Non-current portion	6,844	5,744
Total inventories	$ 68,648	$ 63,298

PROPERTY, PLANT AND EQUIPMENT -

PROPERTY, PLANT AND EQUIPMENT - Schedule (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 1,069,348	$ 994,478
Less: Accumulated depreciation and depletion	(67,108)	(58,735)
Property, plant and equipment, net	1,002,240	935,743
Land and land improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	16,112	16,102
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	15,856	15,111
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	275,541	186,388
Assets under construction
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	323,444	338,482
Mineral rights
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 438,395	$ 438,395

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details)	3 Months Ended
	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($) a	Feb. 28, 2022 USD ($)	Nov. 30, 2020 USD ($)
Property, Plant and Equipment [Line Items]
Capitalized expenditures	$ 74,300,000	$ 68,000,000
Assets transferred	86,400,000
Technology investment agreement, stage II optimization contribution	100,000			$ 9,600,000
Proceeds from technology investment agreement, stage II optimization contribution	0	5,100,000
HREE Production Project Agreement, Stage II Optimization Contribution			$ 35,000,000
Asset impairment charges	0	$ 0
Demolition costs	2,500,000
Machinery and equipment
Property, Plant and Equipment [Line Items]
Assets transferred	$ 85,700,000
TEXAS
Property, Plant and Equipment [Line Items]
Area of real estate property | a		18

PROPERTY, PLANT AND EQUIPENT -

PROPERTY, PLANT AND EQUIPENT - Depreciation and Depletion Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 5,245	$ 2,101
Depletion expense	$ 2,800	$ 3,069

DEBT OBLIGATIONS - Schedule of

DEBT OBLIGATIONS - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Less: Unamortized debt issuance costs	$ (10,674)	$ (11,556)
Long-term debt, net	679,326	678,444
Convertible Notes due 2026 | Convertible Notes
Debt Instrument [Line Items]
Outstanding balance, gross	$ 690,000	$ 690,000

DEBT OBLIGATIONS - Convertible

DEBT OBLIGATIONS - Convertible Notes (Details) - Convertible Notes due 2026 - Convertible Notes	1 Months Ended	3 Months Ended
	Mar. 31, 2021 USD ($) $ / shares	Mar. 31, 2023 shares
Debt Instrument [Line Items]
Advance funded | $	$ 690,000,000
Interest rate	0.25%
Debt instrument, convertible, conversion price (in dollars per share) | $ / shares	$ 44.28
Debt instrument, convertible, conversion ratio	0.0225861
Debt instrument, convertible, number of equity instruments (in shares) | shares		19,714,266
Effective interest rate		0.51%
Debt term		3 years
Maximum
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	0.0285714

DEBT OBLIGATIONS - Interest Exp

DEBT OBLIGATIONS - Interest Expense, Net (Details) - Convertible Notes due 2026 - Convertible Notes - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Debt Instrument [Line Items]
Coupon interest	$ 431	$ 431
Amortization of debt issuance costs	882	877
Convertible Notes interest expense	$ 1,313	$ 1,308

DEBT OBLIGATIONS - Equipment No

DEBT OBLIGATIONS - Equipment Notes (Details) - Equipment notes - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Equipment notes
Current	$ 2,327	$ 2,392
Non-current	4,187	4,743
Notes payable	$ 6,514	$ 7,135
Minimum
Debt Instrument [Line Items]
Debt term	4 years
Interest rate	0%
Maximum
Debt Instrument [Line Items]
Debt term	5 years
Interest rate	6.50%

ASSET RETIREMENT AND ENVIRONM_2

ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligation, current	$ 0.2	$ 0.2
Estimated undiscounted cash flows, to satisfy obligation	$ 50.3	50.4
Remediation term	25 years
Discount rate	2.93%
Environmental obligations, undiscounted cost	$ 27	27.2
Environmental obligations, current	0.5	0.5
Closure and reclamation obligations, financial assurances	$ 43.5	$ 43.5
Minimum
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligations, credit-adjusted risk free rate	6.50%
Maximum
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligations, credit-adjusted risk free rate	12%

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Effective tax rate	17.30%	24.50%

STOCK-BASED COMPENSATION - Addi

STOCK-BASED COMPENSATION - Additional Information (Details)	3 Months Ended
	Mar. 31, 2023 shares
2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)	6,326,026
2023 Performance Share Plan | Market-Based PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted (in shares)	62,709
Vesting period	3 years
Requisite service period	3 years
2023 Performance Share Plan | Market-Based PSUs | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of the awards granted (as a percent)	0%
2023 Performance Share Plan | Market-Based PSUs | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage of the awards granted (as a percent)	200%

STOCK-BASED COMPENSATION - Sche

STOCK-BASED COMPENSATION - Schedule of Stock-Based Compensation and Related Income Tax Benefit (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 7,013	$ 9,773
Stock-based compensation capitalized to property, plant and equipment, net	745	406
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,122	715
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	5,774	8,968
Advanced projects, start-up, development and other
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 117	$ 90

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financial assets:
Cash and cash equivalents	$ 651,215	$ 136,627
Level 1
Financial assets:
Cash and cash equivalents	651,215	136,627
Short-term investments	517,831	1,045,718
Restricted cash	3,151	6,882
Level 1 | Convertible Notes
Financial liabilities:
Debt fair value	652,485	610,650
Level 1 | Equipment notes
Financial liabilities:
Debt fair value	0	0
Level 2
Financial assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Restricted cash	0	0
Level 2 | Convertible Notes
Financial liabilities:
Debt fair value	0	0
Level 2 | Equipment notes
Financial liabilities:
Debt fair value	6,350	6,807
Level 3
Financial assets:
Cash and cash equivalents	0	0
Short-term investments	0	0
Restricted cash	0	0
Level 3 | Convertible Notes
Financial liabilities:
Debt fair value	0	0
Level 3 | Equipment notes
Financial liabilities:
Debt fair value	0	0
Carrying Amount
Financial assets:
Cash and cash equivalents	651,215	136,627
Short-term investments	517,831	1,045,718
Restricted cash	3,151	6,882
Carrying Amount | Convertible Notes
Financial liabilities:
Debt fair value	679,326	678,444
Carrying Amount | Equipment notes
Financial liabilities:
Debt fair value	6,514	7,135
Fair Value
Financial assets:
Cash and cash equivalents	651,215	136,627
Short-term investments	517,831	1,045,718
Restricted cash	3,151	6,882
Fair Value | Convertible Notes
Financial liabilities:
Debt fair value	652,485	610,650
Fair Value | Equipment notes
Financial liabilities:
Debt fair value	$ 6,350	$ 6,807

EARNINGS PER SHARE - Schedule o

EARNINGS PER SHARE - Schedule of Weighted Average Number of Shares (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Class of Warrant or Right [Line Items]
Weighted-average shares outstanding, basic (in shares)	176,881,723	176,355,566
Assumed conversion of Convertible Notes (in shares)	15,584,409	15,584,409
Weighted-average shares outstanding, diluted (in shares)	193,613,539	193,490,330
Restricted Stock
Class of Warrant or Right [Line Items]
Assumed conversion of restricted stock awards (in shares)	723,145	1,148,539
RSUs
Class of Warrant or Right [Line Items]
Assumed conversion of restricted stock awards (in shares)	424,262	401,816

EARNINGS PER SHARE - Calculatio

EARNINGS PER SHARE - Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Calculation of basic EPS:
Net income	$ 37,447	$ 85,551
Weighted-average shares outstanding, basic (in shares)	176,881,723	176,355,566
Basic EPS (in USD per share)	$ 0.21	$ 0.49
Calculation of diluted EPS:
Interest expense on convertible debt, net of tax	$ 1,086	$ 988
Diluted income	$ 38,533	$ 86,539
Weighted-average shares outstanding, diluted (in shares)	193,613,539	193,490,330
Diluted EPS (in USD per share)	$ 0.20	$ 0.45
Effective tax rate	17.30%	24.50%

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - Affiliated Entity - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Related Party Transaction [Line Items]
Revenue from related parties		$ 89.1	$ 155
Purchases from related party		0.9	1.2
Accounts receivable		18.8		$ 29.8
Non-Concentrate Products
Related Party Transaction [Line Items]
Revenue from related parties			4.1
Offtake Agreement
Related Party Transaction [Line Items]
Initial term	2 years
Extension period	1 year
Shipping And Freight Related Agreements With Shenghe
Related Party Transaction [Line Items]
Expenses from transactions with related party		$ 22.7	$ 22.6
VREX Tolling Agreement
Related Party Transaction [Line Items]
Initial term		3 years
Extension period		3 years

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Supplemental cash flow information:
Cash paid for interest	$ 105	$ 83
Cash payments related to income taxes	0	2,500
Change in construction payables	(130)	13,096
Supplemental non-cash investing and financing activities:
Revenue recognized in exchange for debt principal reduction	$ 0	$ 13,566