I managed to derive the formula for the terminal value in the special case of g = 0.
In the special case of g = 0, the terminal value in the question above is the sum of this geometric series:
terminal value = [FCF_5 / (1 + r)^5] + [FCF_5 / (1 + r)^6] + [FCF_5 / (1 + r)^7] + ...
Or equivalently:
terminal value = (FCF_5 / (1 + r)^5) (1 + [1 / (1 + r)^1] + [1 / (1 + r)^2] + ...)
Let s = (1 + [1 / (1 + r)^1] + [1 / (1 + r)^2] + ...), so
terminal value = (FCF_5 / (1 + r)^5) (s)
To calculate the sum of the geometric series s, use the formula for the geometric series as the number of terms approaches infinity:
s = α / (1 - β), for |β| < 1
Substituting α = 1 and common ratio β = 1 / (1 + r) into the geometric series formula and rearranging, we get:
s = (1 + r) / r
Now, substitute s and rearrange to get the formula for the terminal value:
terminal value = (FCF_5 / (1 + r)^5) (s)
terminal value = (FCF_5 / (1 + r)^5) ([1 + r] / r)
terminal value = FCF_5 / [(1 + r)^4 (r)]
I also managed to derive the formula for the terminal value as shown in the question (where g can be ≠ 0).
The terminal value in the question above is the sum of this geometric series, with free cash flow growing by a constant percentage g every year:
terminal value = [FCF_5 / (1 + r)^5] + [(FCF_5)(1 + g)^1 / (1 + r)^6] + [(FCF_5)(1 + g)^2 / (1 + r)^7] + ...
Or equivalently:
terminal value = [FCF_5 / (1 + r)^5] (1 + [(1 + g) / (1 + r)]^1 + [(1 + g) / (1 + r)]^2 + ...)
Let s = (1 + [(1 + g) / (1 + r)]^1 + [(1 + g) / (1 + r)]^2 + ...), so
terminal value = (FCF_5 / (1 + r)^5) (s)
To calculate the sum of the geometric series s, use the formula for the geometric series as the number of terms approaches infinity:
s = α / (1 - β), for |β| < 1
Substituting α = 1 and common ratio β = (1 + g) / (1 + r) into the geometric series formula and rearranging, we get:
s = (1 + r) / (r - g)
Now, substitute s and rearrange to get the formula for the terminal value:
terminal value = (FCF_5 / (1 + r)^5) (s)
terminal value = (FCF_5 / (1 + r)^5) ([1 + r] / [r - g])
terminal value = FCF_5 / [(1 + r)^4 (r - g)]
Todo:
- Find an intuitive explanation of the formula.