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

jusplainjim

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

Kevo

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

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.

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

Thanks Mark,

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

Jim