Material Adverse Change (a.k.a. MAE — Material Adverse Effect) clause in a definitive merger agreement that permits the buyer to walk away without paying the breakup fee if the target suffers a ``material adverse effect'' on its business, financial condition, or results of operations between signing and closing. Courts (especially Delaware) have set a very high bar — the impact must be durationally significant and disproportionately affect the target relative to its industry. Industry-wide downturns, macro shocks, and the deal's own announcement effects are typically carve-outs.