# Technical Studies Reference

### STIX

The STIX (Short Term IndeX) is a short-term trading oscillator that was published in The Polymetric Report. It compares the amount of volume flowing into advancing and declining stocks.

Add this study to a Historical chart for a symbol which indicates the number of advancing issues. Normally this will be the ADV-NYSE symbol. For more information, refer to Market Statistics. And add the Add Additional Symbol study to the chart to load data for the declining issues symbol. Normally this will be the DECL-NYSE symbol.

Let $$N^{(A)}_t$$ and $$N^{(D)}_t$$ be the Number of Advancing Issues and Number of Declining Issues at Index $$t$$. We denote the value of STIX at Index $$t$$ as $$STIX_t$$, and we compute it as follows.

$$t = 0:$$
$$\displaystyle{STIX_0 = \left\{ \begin{matrix} 9\cdot\frac{N^{(A)}_t}{N^{(A)}_t + N^{(D)}_t} + 0.91\cdot\left(.9\cdot\frac{N^{(A)}_t}{N^{(A)}_t + N^{(D)}_t}\right) & N^{(A)}_t \neq 0 \space and \space N^{(D)}_t \neq 0 \\ 0 & otherwise \end{matrix}\right .}$$
$$t > 0:$$
$$\displaystyle{STIX_t = \left\{ \begin{matrix} 9\cdot\frac{N^{(A)}_t}{N^{(A)}_t + N^{(D)}_t} + 0.91 \cdot STIX_{t - 1} & N^{(A)}_t \neq 0 \space and \space N^{(D)}_t \neq 0 \\ STIX_{t - 1} & otherwise \end{matrix}\right .}$$