Describe the cross-check between the Gordon growth and exit multiple methods. Why is this considered a critical step rather than an optional nicety?

What the interviewer is actually testing

Terminal value is one of the highest-yield technical topics because it's where DCF theory meets real judgment, and interviewers use it to separate candidates who plug a formula from those who understand why the formula is dangerous.

The core signals of mastery:

1. You state, unprompted, that terminal value is usually 60-80% of total DCF value. This single fact reframes the whole conversation: most of a DCF's answer comes from the part you can least confidently forecast.

2. You can write both formulas cold: Gordon growth (FCF(n+1) / (WACC − g)) and exit multiple (EBITDA(n) × multiple), and explain the economic story behind each, not just recite them.

3. You anchor g to GDP growth, and can explain why mathematically (WACC > g is required, or the perpetuity diverges) and economically (no company outgrows the whole economy forever).

4. You volunteer the cross-check between methods before being asked. This is the single highest-signal move on this topic: "I'd compute the Gordon growth TV and check what exit multiple it implies against where the comps actually trade."

5. You know the practical convention: exit multiples are more common in real banking work because they're market-grounded and intuitive to clients, while Gordon growth is theoretically cleaner, and a strong candidate can argue either side depending on context (cyclical business, stable comps, academic vs. pitch-book use).

Weak candidates can state the formulas but freeze when asked to defend a specific g or multiple, or don't realize the two methods should reconcile with each other.

Common traps

Trap 1: Using a growth rate above long-run GDP. Plugging in the company's explicit-period growth rate (say 8%) as the perpetuity g wildly overstates terminal value and is economically impossible over an infinite horizon.

Say it out loud: "Perpetuity growth has to be a long-run sustainable rate, generally close to nominal GDP growth (2 to 4 percent) because no company can outgrow the entire economy forever."

Trap 2: Building a WACC-vs-g cell where g ≥ WACC. This produces a negative or infinite terminal value, which is a red flag the candidate doesn't understand the perpetuity math.

Say it out loud: "WACC has to exceed g or the growing perpetuity formula diverges to infinity: that's a hard constraint, not just a modeling convention."

Trap 3: Never cross-checking the two methods against each other. Presenting a Gordon growth terminal value without checking what exit multiple it implies (or vice versa) misses the single most important sanity check in DCF work.

Say it out loud: "Whichever method I lead with, I'd back into what it implies under the other method and compare that to where peers actually trade: if my perpetuity growth assumption implies a 15x exit multiple against a 9x comp set, my assumptions aren't internally consistent."

Trap 4: Using the current, high trading multiple as the exit multiple without adjustment. If the peer set currently trades at an inflated multiple (bubble conditions, a temporary re-rating), extending that multiple 5-10 years out assumes today's sentiment persists indefinitely.

Say it out loud: "I'd sanity-check whether today's trading multiple reflects a temporary premium or a sustainable level: if the sector is trading rich relative to history, I might use a more normalized, slightly lower exit multiple."

Trap 5: Forgetting to discount the terminal value back to present. Terminal value is computed as of year n; failing to discount it back n years overstates enterprise value enormously (often by 40%+).

Say it out loud: "Terminal value is a year-n figure: I still need to discount it back to today at the same WACC and same number of periods as any other year-n cash flow."

Trap 6: Applying the exit multiple to the wrong metric or a distorted terminal-year figure. Using a cyclically peaked or one-time-inflated terminal-year EBITDA overstates the terminal value regardless of which multiple is chosen.

Say it out loud: "I'd make sure the terminal-year EBITDA is a normalized, representative figure (not an artificially high or low year) before applying the exit multiple."