Re: FinancialData errors
- To: mathgroup at smc.vnet.net
- Subject: [mg120600] Re: FinancialData errors
- From: Michael Stern <nycstern at gmail.com>
- Date: Sat, 30 Jul 2011 06:02:52 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201107222344.TAA28525@smc.vnet.net> <201107291202.IAA15679@smc.vnet.net>
1. JANFX is an open-ended mutual fund, so the price changes only once
per day.
2. Per Bloomberg, the proper prices for the days queried were
2/09 10.38
2/10 10.36
2/11 10.37
This agrees with the original poster's experience.
3. FinancialData was returning incorrect results to the original poster.
4. I just ran the original poster's code and it gave me the wrong prices
too. It's returning the correct fund name, so this looks like an error
in the price database that Wolfram is tapping.
5. On the basis of this example alone, I would not use FinancialData[]
for anything, ever.
On 7/29/2011 8:02 AM, Pierpaolo Bernardi wrote:
> On Fri, Jul 29, 2011 at 10:41, DrMajorBob<btreat1 at austin.rr.com> wrote:
>> FUNNY STORY: Here is Tech Support's non-response to my problem, described
>> farther down:
>> I've found a new (to me) species of error in FinancialData.
>>
>> One example is the price of the following stock on Feb 10, 2011:
>>
>> s = "JANFX";
>> FinancialData["JANFX", "Name"]
>> FinancialData["JANFX", {{2011, 2, 9}, {2011, 2, 11}}]
>>
>> "Janus Flexible Bond Fund D Shar"
>>
>> {{{2011, 2, 9}, 10.25}, {{2011, 2, 10}, 10.23}, {{2011, 2, 11},
>> =C2 =C2 10.24}}
>>
>> As you see, FinancialData says the price was 10.23.
>>
>> But I BOUGHT the stock through Janus Funds on that day, and the price was
>> 10.36.
>>
>> Moreover, if I go to Yahoo's interactive price chart for the stock at the
>> following page, 10.36 is the price I find:
> Prices do vary continuously, they don't stay the same for a whole day,
> At the moment you bought it was 10.36. At the moment the data source
> was sampled it was 10.23. Usually historical data use the closing
> price, AFAIK. I see nothing strange in this.
>
>> So... where are the errors really coming from?
>>
>> This is not an astronomically large price or a Missing["Not Available"]
>> price; it's within 2% of the correct price. But it's wrong.
>>
>> These errors make it very difficult to trust FinancialData for any useful
>> purpose.
> If a difference of less than 2% in the historical market data
> influences your algorithms, I won't trust your conclusions. :)
>
> Cheers
>
- References:
- Re: FinancialData still broken
- From: DANA DELOUIS <dana.del@gmail.com>
- Re: FinancialData errors
- From: Pierpaolo Bernardi <olopierpa@gmail.com>
- Re: FinancialData still broken