Geometric Brownian Motion - Solving The SDE

Solving The SDE

For an arbitrary initial value S0 the above SDE has the analytic solution (under Itō's interpretation):

To arrive at this formula, let us divide the SDE by, and write it in Itō integral form:

Of course, looks like having a lot to do with the derivative of ; however, being an Itō process, we need to use Itō calculus: by Itō's formula, we have

Plugging back to the equation we got from the SDE, we obtain

Exponentiating gives the solution claimed above.

Read more about this topic:  Geometric Brownian Motion

Famous quotes containing the words solving the and/or solving:

    More than a decade after our fellow citizens began bedding down on the sidewalks, their problems continue to seem so intractable that we have begun to do psychologically what government has been incapable of doing programmatically. We bring the numbers down—not by solving the problem, but by deciding it’s their own damn fault.
    Anna Quindlen (b. 1952)

    Science is a dynamic undertaking directed to lowering the degree of the empiricism involved in solving problems; or, if you prefer, science is a process of fabricating a web of interconnected concepts and conceptual schemes arising from experiments and observations and fruitful of further experiments and observations.
    James Conant (1893–1978)