Patrick, Current data is available earlier but at least with my downloader there is not much difference in speed when I download data on a daily basis which also automatically includes AX previous days (user defined AX).
If one insists on using current data quotes for Vernon's EOD situation (as opposed to intraday where streaming is preferred) then yes you have to make sure that things get adjusted. One can pay a service to do this or use a downloader that knows when an adjustment for dividend or split is needed and just does it. With such a downloader your concern about extra work for adjustments is not a problem because there is none. However, current for EOD is not the way to go, imo. Waiting a few hours for historical data is worth it in my book in order to ensure that bad data points which bedevil all current data feeds have been corrected, although to be sure I found that most of the time there is no difference between current and historical except perhaps for things like volume, picking up AH quotes, etc. which can be a pain. However, if one really wants to use current data for EOD then perhaps the best approach is to use current for trading days and once a week go back and pick up the historical data in order to ensure that all is OK. That way one has the data a couple of hours earlier but the data base is historical with a few days of current data tacked on. Personally, I would not want uncorrected current data as my "permanent" data set. As for new listing, etc. yes you have to take care of this yourself. I do this for ETFs and it is not a big deal as there are freebid listings that are published periodically so one only has to enter them into the database - a few minutes per month - and nothing is lost because I require a fair amount of data before I use the price series for trading purposes. Similar listings are, I'm sure, available for IPOs, etc., including stuff from brokers who fall all over themselves to give clients that type of information. As for using Yahoo for just a few symbols I guess I'm the exception to your rule as my database consists of about 1000 symbols. However, if one wants something special that a fee-based service provides then that is clearly the way to go. For the rest of us Yahoo and such are just fine. Bill ----- Original Message ----- From: NW Trader To: [email protected] Sent: March 10, 2010 7:49 PM Subject: {Resending}] Re: [amibroker] Few Newbie Questions re: yahoo data Hi Bill, I suppose you are right, however if one is updating daily with the current day feed (much faster and available earlier than historical) the data is not adjusted. You either have to do that chore yourself, or periodically (weekly??) re-download your entire symbol list from the historical site, which I am assuming will overwrite the non split adjusted info. While it is possible to write an exploration to spot possible split candidates (based on price changes between days), one still needs to verify the split and the ratio. For me, my time is worth more than the $1 to $2 daily for data versus my effort to keep a sizable databases current. But that still doesn't solve the symbol change and new symbols problem. Today, for example, BALT (Baltic Trading, Inc., a marine shipper) started trading. If you happened to watch for new listings then you might know of it. If not, then it may be some time before you happen to learn about it. IPOs are often good to watch when they first start out. A data service will automatically pick it up and add it and you can refresh you AB database to add it. However if you only trade a few symbols, then Yahoo certainly can answer the need. Peace and Justice --- Patrick ----- Original Message ----- From: wavemechanic To: [email protected] Sent: Wednesday, March 10, 2010 11:36 AM Subject: Re: [amibroker] Few Newbie Questions re: yahoo data Yahoo does provide adjusted split/dividend data for their "historical" data. So, if downloading historical the downloader should be able to handle this adjustment to the database. Bill ----- Original Message ----- From: NW Trader To: [email protected] Sent: March 09, 2010 2:20 AM Subject: Re: [amibroker] Few Newbie Questions re: yahoo data Hi Vernon, I suppose the fast answer is "It depends". On what does it depend? Well really how are you using the data and for what stocks. First of all, Yahoo data is WYSIWYG, i.e. it doesn't adjust for splits, symbol changes, etc. So if your principal use is to acquire a historic database to back test against, do so with extreme caution. If you are planning on maintaining a large number of symbols to track on a day to day basis to make EOD trading decisions for trades the next day, again the caveat "be careful and double check with another data source before placing trades" (you broker's data is probably sufficient here). If you are going to follow only a few (say 50 or fewer) stocks, then it may be fine. Why? Well as I said, Yahoo data is WYSIWYG and you will have to do all the adjustments for splits, symbol changes, etc. which means spending some amount of time tracking down that info in press releases, SEC filings, etc. On a large database this quickly becomes very time consuming. Your time is a resource and is better spent trading, preparing to trade, learning to trade, studying the markets, etc. Thus, if you are really trading (or even investing by buying and selling more than a couple dozen times a year), you are better off spending the nominal amount to buy a data service that will maintain all that stuff for you and do so with reliable accuracy. Quotes Plus, TeleChart 2007, Premium Data from Norgate are all reasonably priced EoD data providers (think like a couple lattes a week) which integrate with AB nearly seamlessly. Another route to go is feed you broker's data to QuoteTracker and then import it into AB. This won't give you an instant lengthy historical database, but again depending on the number of stocks you plan to follow can be manageable. Keep in mind also that your costs for data feeds (like investment subscriptions and AB) is a tax deductible expense incurred to generate income. If you do decide to go cheap (remember the adage "you get what you pay for" seems to have been invented for data feeds) and stay with free Yahoo data, pay close attention to daily highs and lows as well as open and closing prices and volume. Often there isn't too great a difference, but if you are using indicators which are based on these data points, be wary. Peace and Justice --- Patrick ----- Original Message ----- From: vernon To: [email protected] Sent: Monday, March 08, 2010 4:30 PM Subject: Re: [amibroker] Few Newbie Questions re: yahoo data Hi - Like wise, I am a "newbee" to all this. I had no intentions of becoming a programer, but I do like Amibroker. While I'm learning (and losing money <kidding>), I am using yahoo EOD data during my learning process. It appears to agree with my Scottrade Account (although I haven't done any investigation into the accuracy). I have no desire to use RT data - EOD is fine for my uses. Could someone expand or provide more information with regard to the statement below of "yahoo EOD data being inaccurate"? That worries me a little since I'm investing my hard earned $$$$ using it. Thanks in advance for any insite/information you might provide. As to when EOD data can be downloaded, I generally d/l it between 6 and 7 pm ET. If "historical" d/l doesn't pick it up, "current day" will. Vernon -- ENJOY LIFE!! Keep it SIMPLE!! -----Original Message----- From: [email protected] Sent: Mon, 8 Mar 2010 11:38:39 -0700 To: [email protected] Subject: Re: [amibroker] Few Newbie Questions Hi Jchi -- High quality, low cost end-of-day data is available from several vendors. Two I recommend (I subscribe to them both) are: Quotes Plus -- http://qp2.com/joomla/index.php Norgate Premium Data -- http://www.premiumdata.net/ Read the reference materials related to BuyPrice, SellPrice, and TradeDelays. They work in combination. The pair of statements BuyPrice = Open; SetTradeDelays(0,x,x,x); uses the price of the open of the bar being processed. The pair of statements BuyPrice = Open; SetTradeDelays(1,x,x,x); uses the price of the open of the bar following the bar being processed. Thanks, Howard On Fri, Feb 26, 2010 at 3:58 PM, jchi18 <[email protected]> wrote: 1. When is the earliest I can download EOD data from Yahoo? i.e., when will today's data be available for download? 2. In the trades tab when performing automatic analysis, what does buy price mean if I set it to open? i.e., I perform a scan of my trading system and it says that a buy signal was found for 2/26/10. When it is set to buy at the open price, will amibroker get the open price of 2/26 or 2/27? 3. What is the best but reasonably priced way of getting accurate EOD data into amibroker? I understand that Yahoo is inaccurate. Feel free to contact me at [email protected]. THanks. ------------------------------------------------------------------------ Free 3D Marine Aquarium Screensaver Watch dolphins, sharks & orcas on your desktop! Check it out at www.inbox.com/marineaquarium
