Thanks to Professor Brian Quinn (Boston College) for passing along the video posted below on "Material Adverse Change" in the M&A Context (Part 1) from law firm Weil Gotshal.  Weil Gotshal has posted a number of similar clips, which I have found useful in the past. 

This past Sunday, Robert B. Schumer (Paul Weiss) authored a related post over at the Harvard Law School Forum on Corporate Governance and Financial Regulation.  His post is entitled "Delaware Court: Missed Sales Forecasts Could be 'Material Adverse Effect"' and opens with the following paragraph:

In Osram Sylvania Inc. v. Townsend Ventures, LLC, the Delaware Court of Chancery (VC Parsons) declined to dismiss claims by Osram Sylvania Inc. that, in connection with OSI’s purchase of stock of Encelium Holdings, Inc. from the company’s other stockholders (the “Sellers”), Encelium’s failure to meet sales forecasts and manipulation of financial results by the Sellers amounted to a material adverse effect (“MAE”). The decision was issued in the context of post-closing indemnity claims asserted by OSI against the Sellers and not a disputed closing condition.

Few, if any, Delaware cases have found a triggering of a MAC/MAE clause, but such cases obviously depend on the wording of the agreement and the relevant facts.  Read the entire post here.