Multifractals

The f(α) Curve from Financial Data

As an example, we collect time series of daily closing prices of six stocks,
AIVSX (Investment company of America), APPL (Apple), CSCO (Cisco), GE, IBM, and INTC (Intel)
All data go to June 8, 2005, and have these starting dates
AIVSX  June 3, 1996   2270 trading days
CSCO   March 26, 1990   3834 trading days
INTC   July 9, 1986   4774 trading days
APPL   Sept 6, 1984   5237 trading days
IBM   Jan 2, 1962   10934 trading days
GE   Jan 2, 1962   10934 trading days
The f(α) curves were generated by the method of moments using our fractal statistics software, with q ranging from -20 to 20, an α step of 0.01, and a q step of 0.1.
To illustrate this, use the Intel data.
Here are other data sets we use. APPL, AIVSX, IBM, GE, and CSCO.
In all windows, the horizontal axis (α) ranges from 0 to 2 and the vertical axis (f(α)) ranges from 0 to 1.
For comparison, here are the time series and the driven IFS. For the driven IFS we plot differences using mean-centered bins with first and third bin boundaries one standard deviation above and below the mean.
AIVSXAPPL
CSCOGE
IBMINTC
Finally, here are the observed α ranges.
AIVSX  .90 <= α <= 1.73  APPL  .87 <= α <= 1.11
CSCO  .68 <= α <= 1.29  GE  .87 <= α <= 1.78
IBM  .78 <= α <= 1.47  INTC  .77 <= α <= 1.50

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