How finance LLMs break, named.

Errors that surface as the wrong framework applied confidently, a yield where a recovery is required, a levered beta against unlevered cash flows, a perpetuity that assumes the impossible.

Where several accounting and financing conventions have to hold at once. Get four of five right and the number still cannot be signed. Synthesis errors across sections, not slips inside one.

Governed by defined terms, not GAAP. A covenant EBITDA, a yield to worst, a subordination waterfall — each a contractual construct a model tends to replace with its nearest textbook cousin.

Punishes framework substitution and convention drift. A greater-of payoff modeled as a sum, a square-root time-scaling dropped, a forward quoted additively rather than as a rate ratio.

The quiet ones — a sign convention, an effective-versus-cash-rate slip, a permanent difference treated as if it reverses. Small individually; they propagate through all three statements.