Natural logarithm

1. Options analysis

The natural logarithm ln(x) is the logarithm to the base ‘e’, and mathematically the inverse function of the exponential function e^x.

So for example ln(100) = 4.60517...

And e^4.60517... = 100

Also known for short as the 'natural log'.

Also sometimes known - loosely - as the 'Napierian logarithm'.

(Not to be confused with Lognormal, which is different.)

2. Maths

The natural log - as used in options analysis above - is exactly the same as the concept used more broadly in maths and financial maths applications.

See also