Group 1 - The solar energy sector in the US saw significant stock gains, with companies like Sunrun, Daqo New Energy, and Canadian Solar rising over 7% [1] - The upcoming tax guidance from the US Treasury poses a threat to the financial viability of numerous clean energy projects across the country [1] - The core controversy revolves around changes in the eligibility criteria for clean energy tax credits, which may increase the threshold for developers to qualify for tax subsidies [1] Group 2 - The new regulations, if implemented, could lead to many projects that rely on tax credits for profitability losing their eligibility, potentially resulting in project cancellations [1] - The Trump administration's recent executive order mandates the Treasury Department to significantly raise the qualification standards for tax credits [1] - Developers may be required to provide more evidence of construction progress to meet the new criteria [1]