# Technical Studies Reference

### Up/Down Volume Ratio

The study calculates and displays a moving average of the Up/Down Ratio. The method of calculation for this Ratio depends on the setting of the Calculation Based On Input.

The Up/Down Ratio at Index $$t$$ is denoted as $$UDR_t$$. For all of the variables in the following formulas, the subscript $$t$$ indicates that we are specifying the values of these variables at Index $$t$$.

If Calculation Based On is set to Up/Down Volume, then the following variables are used in this study.

Complete descriptions of these variables can be found in the documentation on sc.BaseDataIn[][] / sc.BaseData[][].

• $$V^{(U)}_t$$ = sc.BaseData[SC_UPVOL][sc.Index] = sc.UpTickVolume[sc.Index]
• $$V^{(D)}_t$$ = sc.BaseData[SC_DOWNVOL][sc.Index] = sc.DownTickVolume[sc.Index]

The Up/Down Ratio is denoted as $$UDR_t$$, and it is computed as follows.

$$\displaystyle{UDR_t = \left\{ \begin{matrix} 100\cdot\frac{V^{(U)}_t - V^{(D)}_t}{V^{(U)}_t + V^{(D)}_t} & V^{(U)}_t + V^{(D)}_t \neq 0 \\ 0 & V^{(U)}_t + V^{(D)}_t = 0 \end{matrix}\right .}$$

If Calculation Based On is set to Ask/Bid Volume, then the Ask Volume and Bid Volume are used in the calculation, as follows.

$$\displaystyle{UDR_t = \left\{ \begin{matrix} 100\cdot\frac{V^{(ask)}_t - V^{(bid)}_t}{V^{(ask)}_t + V^{(bid)}_t} & V^{(ask)}_t + V^{(bid)}_t \neq 0 \\ 0 & V^{(ask)}_t + V^{(bid)}_t = 0 \end{matrix}\right .}$$

If Calculation Based On is set to Up/Down Trades, then the Number of Trades - Ask and Number of Trades - Bid are used in the calculation, as follows.

$$\displaystyle{UDR_t = \left\{ \begin{matrix} 100\cdot\frac{N^{(ask)}_t - N^{(bid)}_t}{N^{(ask)}_t + N^{(bid)}_t} & N^{(ask)}_t + N^{(bid)}_t \neq 0 \\ 0 & N^{(ask)}_t + N^{(bid)}_t = 0 \end{matrix}\right .}$$

Let $$n$$ denote the Moving Average Length Input. The Subgraph that is displayed is the Exponential Moving Average of the Up/Down Ratio: $$EMA_t(UDR,n)$$.

Note: Depending on the setting of the Input Moving Average Type, the Exponential Moving Average in the above formula could be replaced with a Linear Regression Moving Average, a Simple Moving Average, a Weighted Moving Average, a Wilders Moving Average, a Simple Moving Average - Skip Zeros, or a Smoothed Moving Average.