> For the complete documentation index, see [llms.txt](https://indicators.agenatrader.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://indicators.agenatrader.com/standard-indicators/true-strength-index-tsi.md).

# True Strength Index (TSI)

#### Description <a href="#description_127" id="description_127"></a>

The True Strength Index (TSI) is a momentum indicator. It is used as an indicator for trend direction and for displaying overbought or oversold conditions. As a rule, momentum oscillators preemptively indicate price changes, whereas moving averages generally lag behind the price. The TSI brings together the advantages of these two indicator groups.

#### Interpretation <a href="#interpretation_59" id="interpretation_59"></a>

The TSI line moves between 100 and -100. Most values are between +25 and -25. These trigger lines can be used to anticipate overbought or oversold situations. A rising TSI signals an uptrend, while falling TSI suggests a downtrend.

#### Further information <a href="#further-information_44" id="further-information_44"></a>

<http://en.wikipedia.org/wiki/True_strength_index>

#### Usage <a href="#usage_114" id="usage_114"></a>

```csharp
TSI(int fast, int slow)
TSI(IDataSeries inSeries, int fast, int slow)
TSI(int fast, int slow)[int barsAgo]
TSI(IDataSeries inSeries, int fast, int slow)[int barsAgo]
```

#### Return value <a href="#return-value_112" id="return-value_112"></a>

**double**

When using this method with an index (e.g. **TSI**(3,14)\[**int** barsAgo] ), the value of the indicator will be issued for the referenced bar.

#### Parameters <a href="#parameters_104" id="parameters_104"></a>

inSeries Input data series for the indicator

fast Number of bars included in the calculation of the fast EMA

slow Number of bars included in the calculation of the slow EMA

#### Visualization <a href="#visualization_116" id="visualization_116"></a>

![True Strength Index (TSI)](https://agenatrader.github.io/AgenaIndicator-documentation/media/TSI.jpg)

#### Example <a href="#example_108" id="example_108"></a>

```csharp
//Output of the current value for the True Strength Index (TSI)
Print("The current value for the TSI is " + TSI(3, 14)[0]);
```