"Does this event trigger the MAC clause?" is a classic M&A interview question because it can't be answered with a single formula. Interviewers use it to check whether a candidate can combine a quantitative test with legal and negotiation judgment — and most candidates fumble it by jumping straight to a percentage decline without addressing the framework around it.
The Three-Part Framework Interviewers Are Listening For
A strong answer to a MAC clause question walks through three layers, in order, rather than jumping straight to a number:
- Does the event fall outside the standard carve-outs? Before touching a materiality threshold, check whether the decline is company-specific or whether it's driven by an excluded category — an industry-wide downturn, a change in law, or the effects of the deal's own announcement. If it's excluded and the target isn't disproportionately worse off than its peers, the analysis often stops here.
- Does it clear the negotiated numeric threshold? Most MAC definitions get anchored, in practice, to some proxy — commonly a percentage decline in EBITDA or revenue relative to a pre-signing baseline. This is the step candidates default to, but it's only the second layer, not the whole answer.
- Is the decline "durationally significant"? Delaware case law requires the deterioration to be expected to persist, not just show up in one bad quarter. A short-term dip — even a large one — usually doesn't qualify.
Worked Example: Applying the Framework
The case MAC Clause and Deal Closing Risk is built around exactly this three-part test: a target loses its largest customer four months after signing, and you're asked to determine whether the resulting EBITDA decline clears a negotiated 20% materiality threshold — and, more importantly, whether that alone would actually hold up as grounds to walk away. Working through the numbers first, then layering on the carve-out and duration questions, is the structure interviewers want to see reproduced out loud.
Why the "Right" Answer Is Usually "No"
A common mistake is assuming that if the interviewer is asking the question, the answer must be "yes, this triggers the MAC." In reality, the historical base rate points the other way: Akorn v. Fresenius (2018) remains the only Delaware case where a MAC was successfully found, and it required a sustained multi-quarter collapse plus separate regulatory violations. Interviewers are often testing whether you know that MAC clauses are deliberately hard to invoke — and that in practice, a bad post-signing event is more likely to trigger a renegotiation of price than an actual walk-away.
It also helps to connect the MAC discussion to the buyer-side incentives at play. If you're asked a related question about deal structure, see Cash vs. Stock Consideration for how the form of payment shifts risk between buyer and seller, or Types of Buyers: Strategic, Private Equity, and Family Office for how different buyer types weigh walk-away risk differently given their return requirements.