Gaps and pre-market

Discussion in 'Trading' started by I$land, Nov 29, 2007.

  1. I$land


    I usually wait about 10 minutes after the open to build a list of gappers (stocks that opened higher/lower than previous day close) because I only traded them later in the day. Now, I would like to trade a few minutes after the open so I need my list of gaps much earlier.

    If a stock gaps up (or down) at the open from the previous day close, does it always mean there was a gap in pre-market ?

    Basically, if I run a gap scan in pre-market, a few minutes before the open, will I have all stocks which will open with a gap ?


  2. I$land


    Anyone ?
  3. We have always had pre-opening indications from the NYSE, until recently that is. They are supposed to start providing that information again this month (still waiting). You can use a scanning type spreadsheet with a dde link to your data feed, or try something like - a very complete scanning system (cheap as well).

  4. I$land


    Don, thank you for your interest but you did not answer my question.

    I know I need to use a market scanner and I do use one.

    Question :

    List1 : scanner ran 1 minute before open to find gaps
    List2 : scanner ran 2 minutes after open to find gaps

    Will List1 EQUAL List2 ?
  5. No. If you use the pre-market scanner, it can be set for "composite" pricing and show the ECN trades. After the market opens it's just going to give you the current exchange (or composite) prices. No reason for them to be the same, regardless of gaps. It would also depend on what price you're "gapping" from...NYSE (or NASDAQ) close, or consolidated'll notice differences when checking prices on Yahoo finance vs. NYSE or other exchanges.

    And, be careful of ex-dividend days of course.


  6. No, it won't be exactly the same. If you run pretty much any scanner at different points in time you'll get different results as things change in the market.

    Generally, stocks that are going to gap a significant amount will have at least some pre-market activity, so running the scan before the opening bell should give you most of the same stocks (assuming your scanner includes ECN prints). If you use a volume filter, some of the thinner stocks may come in under your criteria if it doesn't trade much in the pre-market.

    Basically, you just have to play with it and see.
  7. Aok


    Short answer: No.

    It also depends on what you're searching for.

    All gaps are not created equal. Especially pre market gaps. Look at the link, basically identical screen criteria but the left one is set to pre market and dark grey one is set at market open.

    I am not seeing every gap out there because of my criteria but you get the idea. Gaps are a form of impulse and a great stock play. But you must not forget volume and you must be very focused or extremely nimble. Since I live on left coast all times are Pacific.

    nice link hoodoo. Thanks.
  8. I$land


    Thank you all for your responses.

    hoodooman : thanks for the link ! That pre-market HeatMap is pretty cool.

    Aok : good comments, thanks for the screenshot :)
  9. oddeolab


    What software do you guys use to scan for gaps with realtime data or minimal delay? Tc2000, finviz, trade ideas, stock etc? Thanks for any responses!
    #10     Jul 30, 2015