Exhibit 99.1 Condensed Interim Consolidated Financial Statements For the three and nine months ended September 30, 2023 (expressed in thousands of Canadian dollars) - Unaudited NexGen Energy Ltd. Condensed Interim Consolidated Statements of Financial Position (expressed in thousands of Canadian Dollars) - Unaudited | | | As at September 30, 2023 | | As at December 31, 2022 | | --- | --- | --- | --- | --- | | Assets | | | | | | Current assets | | | | | | Cash | $ | 370,444 | $ | 134,447 | | Marketable securi ...