What would have to be true.

The most common move on a hot deal is to argue why it works. The Butterfly Memo panel runs the opposite. For each thesis the deal depends on, the panel asks: what would have to be true for this to fail?

It's not a pre-mortem in the usual sense. It's a structured chain — the thesis, the inversion, the evidence we'd need to disprove the inversion, and the trip-wire we'd watch for over the life of the investment.

Each of the twelve lenses runs WWHTBT in their own voice. Marks looks for the second-order failure. Taleb looks for the fat-tail failure. Bessemer looks for the failure mode you'd publish on the anti-portfolio in five years.

You see all twelve inversions in the memo, side by side. The IC sees the deal's real surface area, not just the founder's slide.