Hot answers tagged mean
7
Take a look at the sde package; specifically the dcOU and dsOU functions. You may also find some examples on the R-SIG-Finance mailing list, which would be in the results of a search on www.rseek.org.
6
The issue for any technique is, does it consistently work as expected in the future? If not, then it's worthless.
The idea behind mean reversion is that you have a "mean" that means something (it's not arbitrary), and a deviation from that mean that reverts in some consistent way. A pair trade is a common form of a "mean reversion" trade.
Below is a ...
6
I think of mean reversion as more of a single stock phenomenon. In aggregate, these ididosyncratic mean reversions should offset one another and make the market smoother than its component stocks.
There is a lot of work on mean reversion at the single stock level. The best entry is Jegadeesh's 1990 paper on what became known as "short run reversal" -- the ...
5
The OU process is:
http://en.wikipedia.org/wiki/Ornstein-Uhlenbeck_process
Here's an example of the use of the OU method.
http://epchan.blogspot.com/2007/01/what-is-your-stop-loss-strategy.html
To me, the problem is identifying processes that actually have a reason to bleed down to the mean, and that show statistically significant results. If you can ...
4
The code of Euler Maruyama simulation method is pretty simple (nu is long run mean, lambda is mean reversion speed):
ornstein_uhlenbeck <- function(T,n,nu,lambda,sigma,x0){
dw <- rnorm(n, 0, sqrt(T/n))
dt <- T/n
x <- c(x0)
for (i in 2:(n+1)) {
x[i] <- x[i-1] + lambda*(nu-x[i-1])*dt + sigma*dw[i-1]
}
return(x);
}
3
You can also use the Sim.DiffProc package.
Have a look at this document:
Sim.DiffProc: A Package for Simulation of Diffusion Processes in R
See esp. chapter 2.1.2
There is even a Graphical User Interface (GUI) available for some functions:
http://cran.r-project.org/web/packages/Sim.DiffProcGUI/index.html
See chapter 4 in the above document for details.
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