SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Technology Stocks : Qualcomm Incorporated (QCOM) -- Ignore unavailable to you. Want to Upgrade?

To: JohnG who wrote (43554)10/6/1999 1:19:00 PM
From: Jim Willie CB  Read Replies (2) | Respond to of 152472
 
JohnG, on exponential moving averages

what you describe is the geometric moving average
essentially it is the n-th root of the product of those n daily closing prices
the logging and exponentiating enables easier calculations
e.g. geometric avg of 2 and 0.5 is 1
of 4 and 0.25 is 1
of 2,4,6,5 is fourth-root of 240, which is about 3.936

exponential moving average is something more queer
I will dig up a formula for you
the exponential portion comes from smoothing
the weights involve a clever scheme of exponential coefficients
imagine a smoothed arithmetic moving average
the object is to remove undue spikeyness

looks like I missed the cupofcoffee by a point -- 206

more later, jim



To: JohnG who wrote (43554)10/6/1999 1:23:00 PM
From: Tlac  Read Replies (2) | Respond to of 152472
 
How do you compute an exponential moving average?

clearstation.com

EMA = price today * K + EMA yest * (1-K)
where K = 2 / (N+1)

An exponential moving average gives more weight to the latest data and responds faster to changes than does a simple MA. At the same time, EMA does not jump in response to old data being dropped off. Again, as Elder says, "This guard dog has better ears, and it only barks once when someone approaches the house."

Kelly


HomeMailHotSubjectMarksPeopleMarksKeepersSettings
Terms Of UseContact UsCopyright/IP PolicyPrivacy PolicyAbout UsFAQAdvertise on SI
© 2026 Knight Sac Media.  Data provided by Twelve Data, Alpha Vantage, and CityFALCON News