[R-SIG-Finance] adjustOHLC discrepancy
Joshua Ulrich
josh.m.ulrich at gmail.com
Sat Oct 6 20:49:14 CEST 2012
Jim,
Looks like the issue was that dividends provided by Yahoo are
back-adjusted for splits. I knew this (see TTR::getYahooData), but
that knowledge didn't find its way into adjustOHLC (until now).
I've updated adjustOHLC on R-Forge (r583) to un-adjust the dividends
before calculating the total adjustment ratio. Please advise if you
(or anyone) notice any issues.
Best,
--
Joshua Ulrich | about.me/joshuaulrich
FOSS Trading | www.fosstrading.com
On Wed, Sep 19, 2012 at 5:23 PM, Jim Green
<student.northwestern at gmail.com> wrote:
> On 19 September 2012 04:00, Jim Green <student.northwestern at gmail.com> wrote:
>> Thanks Josh. I'll dig a little more with your clues and post back if I
>> find anything.
>
> Checked Bloomberg, many of the cacs from are wrong before 2009... some
> even don't make sense..
>
> Nasdaq, on the other hand, seems to have correct historical dividend data
>
> http://www.nasdaq.com/symbol/c/dividend-history
>
> adjusted close provided by yahoo seems reasonable. but need more time to test.
>
>
> Thanks to Josh again for looking into the issue! Hope this post
> answers some potential questions regarding adjustOHLC.
>
>>
>> Jim.
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