How can I scan for an inflection point about a week ago?

jusplainjim
jusplainjim ✭
in Scanning
I am trying to find an inflection point, but all my tries have resulted in a "your scan syntax is incorrect"
What I've tried, among other approaches is:
[8 days ago sma (3,close) > sma 7 days ago(3,close)]
[7 days ago sma (3,close) < sma 6 days ago(3,close)]
What am I doing wrong?
jusplainjim

Best Answers

  • Kevo
    Kevo ✭
    Answer ✓
    I am just commenting on the syntax of the scan. I have no idea what an inflection point is, or the validity of the scan. Maybe someone else can comment on this. What is an inflection point?

    The first thing I noticed is that the "# days ago" is out of order. Also, the keyword "and" is missing, and there were no filters to start with. I like to put the period in the scan just for completeness. So here is the correct syntax:

    [type = stock] AND [Daily SMA(20,Daily Volume) > 40000]

    and [8 days ago daily sma (3,close) > 7 days ago daily sma (3,close)]
    and [7 days ago daily sma (3,close) < 6 days ago daily sma (3,close)]
  • markd
    markd mod
    Answer ✓
    Hi Jim,

    Here's one way to detect a turn in an MA:

    // it's less than just a few days ago
    and [sma(21, close) < 5 days ago sma(21, close)]

    // but higher than a few days before that
    and [sma(21, close) > 10 days ago sma(21, close)]

    // and check that it hasn't turned back up since a few days ago
    and [sma(21, close) < 1 day ago sma(21, close)]

    For each SMA length you have to decide how many days' change in direction really constitutes a turn; the longer the SMA (or EMA) the more days. For 21, 5 seems to do the trick. For a 63 SMA it might be 15 (just guessing). Then you need a number fairly close to your first choice to ensure the turn hasn't gone too far - in this case I arbitrarily chose 10. You'll have to experiment with numbers you like.

Answers

  • jusplainjim
    jusplainjim ✭
    Hi Kevo,
    Thanks you have answered my question, and with your question made me realize my math is rustier than I knew. I am not looking for an inflection point with my scan but a change in direction of a moving average. My interest is to see if changes in moving average direction can be useful in trading, because they will generally come before moving average crossovers.
    Jusplainjim
  • jusplainjim
    jusplainjim ✭
    Thanks Mark,

    You have also answered my question and given me some additional things to incorporate.

    Jim

Categories