Quote from zedDoubleNaught:
- does it make sense?
yes, I totally get your examples. in this case the end numbers do represent something that is meaningful. I would say based on how the numbers were generated, they reflect or correlate with market sentiments.
- ask the question, then try to disprove with events in the data.
By posting here, I was hoping to establish just that, how these indicators work in real time. I am still trying to figure out the best way to backtest, because the two indicators were generated from intraday data of thousands of stocks. And the basket of stocks is a moving target as well. If you have any input on this, I would greatly appreciate it.
- better to use objective numbers for levels or signals than subjective descriptions of 'it's turning down' or 'it's really high'. In real time going forward this won't work very well. When you watch the indicator at the right, it's always turning up or down or really high or low. It's better to ask, 'when it's over 40', or 'when the red line is 10 above the blue line', or similar. Next, if it really does precede a top or bottom, next have to figure out the expected time range of the top or bottom; if you don't know if it's in 1 day or 10 days, it might not work out so well.
great points. it looks to me when the blue line spikes above 20, a local market top follows soon. But I'd have to look into the time range as you suggested.
In terms of the red line, it seems that after it spikes, when it turns back downward below 20, then it may not be a bad time to buy.
It also seems the red line correlates with bottoms better than the blue does tops, wonder if it's because this is a bull market.
- the previous 2 points lead to choosing parameters, and cautions about curve-fitting or over-optimzation. Any indicator can be made to fit any past data with the right parameters, but then it won't work well going forward.
solid point.
- be sure the indicator uses data available at the time of calculation.
All data are realtime data.
- how does the interpolation affect it?
the indicators can be calculated real time intraday, although most of time the market is not volatile enough to justify calculating multiple data points in a trading day. For example, at 10am you can calculate a value on the red line, a value on the blue line, and record SPX at the same time. You can repeat this process as often as you like, and generate much smoother curves, which I don't think would add much value however.