Supported Indicators

True Strength Index

Introduction

This indicator computes the True Strength Index (TSI). The True Strength Index is calculated as explained here: https://school.stockcharts.com/doku.php?id=technical_indicators:True_strength_index Briefly, the calculation has three steps: 1. Smooth the momentum and the absolute momentum by getting an EMA of them (typically of period 25) 2. Double smooth the momentum and the absolute momentum by getting an EMA of their EMA (typically of period 13) 3. The TSI formula itself: divide the double-smoothed momentum over the double-smoothed absolute momentum and multiply by 100 The signal is typically a 7-to-12-EMA of the TSI.

To view the implementation of this indicator, see the LEAN GitHub repository.

Using TSI Indicator

To create an automatic indicators for TrueStrengthIndex, call the TSI helper method from the QCAlgorithm class. The TSI method creates a TrueStrengthIndex object, hooks it up for automatic updates, and returns it so you can used it in your algorithm. In most cases, you should call the helper method in the Initializeinitialize method.

public class TrueStrengthIndexAlgorithm : QCAlgorithm
{
    private Symbol _symbol;
    private TrueStrengthIndex _tsi;

    public override void Initialize()
    {
        _symbol = AddEquity("SPY", Resolution.Daily).Symbol;
        _tsi = TSI(_symbol, 25, 13, 7, MovingAverageType.Exponential);
    }

    public override void OnData(Slice data)
    {
        if (_tsi.IsReady)
        {
            // The current value of _tsi is represented by itself (_tsi)
            // or _tsi.Current.Value
            Plot("TrueStrengthIndex", "tsi", _tsi);
            // Plot all properties of tsi
            Plot("TrueStrengthIndex", "signal", _tsi.Signal);
        }
    }
}
class TrueStrengthIndexAlgorithm(QCAlgorithm):
    def initialize(self) -> None:
        self._symbol = self.add_equity("SPY", Resolution.DAILY).symbol
        self._tsi = self.tsi(self._symbol, 25, 13, 7, MovingAverageType.Exponential)

    def on_data(self, slice: Slice) -> None:
        if self._tsi.is_ready:
            # The current value of self._tsi is represented by self._tsi.current.value
            self.plot("TrueStrengthIndex", "tsi", self._tsi.current.value)
            # Plot all attributes of self._tsi
            self.plot("TrueStrengthIndex", "signal", self._tsi.signal.current.value)

The following reference table describes the TSI method:

tsi(symbol, long_term_period=25, short_term_period=13, signal_period=7, signal_type=1, resolution=None, selector=None)[source]

Creates a TrueStrengthIndex indicator for the symbol. The indicator will be automatically updated on the given resolution.

Parameters:
  • symbol (Symbol) — The symbol whose TSI we want
  • long_term_period (int, optional) — Period used for the first price change smoothing
  • short_term_period (int, optional) — Period used for the second (double) price change smoothing
  • signal_period (int, optional) — The signal period
  • signal_type (MovingAverageType, optional) — The type of moving average to use for the signal
  • resolution (Resolution, optional) — The resolution
  • selector (Callable[IBaseData, float], optional) — x.Value)
Returns:

The TrueStrengthIndex indicator for the given parameters

Return type:

TrueStrengthIndex

TSI(symbol, longTermPeriod=25, shortTermPeriod=13, signalPeriod=7, signalType=1, resolution=None, selector=None)[source]

Creates a TrueStrengthIndex indicator for the symbol. The indicator will be automatically updated on the given resolution.

Parameters:
  • symbol (Symbol) — The symbol whose TSI we want
  • longTermPeriod (Int32, optional) — Period used for the first price change smoothing
  • shortTermPeriod (Int32, optional) — Period used for the second (double) price change smoothing
  • signalPeriod (Int32, optional) — The signal period
  • signalType (MovingAverageType, optional) — The type of moving average to use for the signal
  • resolution (Resolution, optional) — The resolution
  • selector (Func<IBaseData, Decimal>, optional) — x.Value)
Returns:

The TrueStrengthIndex indicator for the given parameters

Return type:

TrueStrengthIndex

If you don't provide a resolution, it defaults to the security resolution. If you provide a resolution, it must be greater than or equal to the resolution of the security. For instance, if you subscribe to hourly data for a security, you should update its indicator with data that spans 1 hour or longer.

For more information about the selector argument, see Alternative Price Fields.

For more information about plotting indicators, see Plotting Indicators.

You can manually create a TrueStrengthIndex indicator, so it doesn't automatically update. Manual indicators let you update their values with any data you choose.

Updating your indicator manually enables you to control when the indicator is updated and what data you use to update it. To manually update the indicator, call the Updateupdate method with time/number pair or an IndicatorDataPoint. The indicator will only be ready after you prime it with enough data.

public class TrueStrengthIndexAlgorithm : QCAlgorithm
{
    private Symbol _symbol;
    private TrueStrengthIndex _tsi;

    public override void Initialize()
    {
        _symbol = AddEquity("SPY", Resolution.Daily).Symbol;
        _tsi = new TrueStrengthIndex(25, 13, 7, MovingAverageType.Exponential);
    }

    public override void OnData(Slice data)
    {
        if (data.Bars.TryGetValue(_symbol, out var bar))
        {      
            _tsi.Update(bar.EndTime, bar.Close);
        }
   
        if (_tsi.IsReady)
        {
            // The current value of _tsi is represented by itself (_tsi)
            // or _tsi.Current.Value
            Plot("TrueStrengthIndex", "tsi", _tsi);
            // Plot all properties of tsi
            Plot("TrueStrengthIndex", "signal", _tsi.Signal);
        }
    }
}
class TrueStrengthIndexAlgorithm(QCAlgorithm):
    def initialize(self) -> None:
        self._symbol = self.add_equity("SPY", Resolution.DAILY).symbol
        self._tsi = TrueStrengthIndex(25, 13, 7, MovingAverageType.Exponential)

    def on_data(self, slice: Slice) -> None:
        bar = slice.bars.get(self._symbol)
        if bar:
            self._tsi.update(bar.EndTime, bar.Close)
        if self._tsi.is_ready:
            # The current value of self._tsi is represented by self._tsi.current.value
            self.plot("TrueStrengthIndex", "tsi", self._tsi.current.value)
            # Plot all attributes of self._tsi
            self.plot("TrueStrengthIndex", "signal", self._tsi.signal.current.value)

To register a manual indicator for automatic updates with the security data, call the RegisterIndicatorregister_indicator method.

public class TrueStrengthIndexAlgorithm : QCAlgorithm
{
    private Symbol _symbol;
    private TrueStrengthIndex _tsi;

    public override void Initialize()
    {
        _symbol = AddEquity("SPY", Resolution.Daily).Symbol;
        _tsi = new TrueStrengthIndex(25, 13, 7, MovingAverageType.Exponential);
        RegisterIndicator(_symbol, _tsi, Resolution.Daily);
    }

    public override void OnData(Slice data)
    {
        if (_tsi.IsReady)
        {
            // The current value of _tsi is represented by itself (_tsi)
            // or _tsi.Current.Value
            Plot("TrueStrengthIndex", "tsi", _tsi);
            // Plot all properties of tsi
            Plot("TrueStrengthIndex", "signal", _tsi.Signal);
        }
    }
}
class TrueStrengthIndexAlgorithm(QCAlgorithm):
    def initialize(self) -> None:
        self._symbol = self.add_equity("SPY", Resolution.DAILY).symbol
        self._tsi = TrueStrengthIndex(25, 13, 7, MovingAverageType.Exponential)
        self.register_indicator(self._symbol, self._tsi, Resolution.DAILY)

    def on_data(self, slice: Slice) -> None:
        if self._tsi.is_ready:
            # The current value of self._tsi is represented by self._tsi.current.value
            self.plot("TrueStrengthIndex", "tsi", self._tsi.current.value)
            # Plot all attributes of self._tsi
            self.plot("TrueStrengthIndex", "signal", self._tsi.signal.current.value)

The following reference table describes the TrueStrengthIndex constructor:

TrueStrengthIndex

class QuantConnect.Indicators.TrueStrengthIndex[source]

This indicator computes the True Strength Index (TSI). The True Strength Index is calculated as explained here: https://school.stockcharts.com/doku.php?id=technical_indicators:true_strength_index Briefly, the calculation has three steps: 1. Smooth the momentum and the absolute momentum by getting an EMA of them (typically of period 25) 2. Double smooth the momentum and the absolute momentum by getting an EMA of their EMA (typically of period 13) 3. The TSI formula itself: divide the double-smoothed momentum over the double-smoothed absolute momentum and multiply by 100 The signal is typically a 7-to-12-EMA of the TSI.

get_enumerator()

Returns an enumerator that iterates through the history window.

Return type:

IEnumerator[IndicatorDataPoint]

reset()

Resets this indicator to its initial state

to_detailed_string()

Provides a more detailed string of this indicator in the form of {Name} - {Value}

Return type:

str

update(time, value)

Updates the state of this indicator with the given value and returns true if this indicator is ready, false otherwise

Parameters:
  • time (datetime)
  • value (float)
Return type:

bool

update(input)

Updates the state of this indicator with the given value and returns true if this indicator is ready, false otherwise

Parameters:
  • input (IBaseData)
Return type:

bool

property consolidators

The data consolidators associated with this indicator if any

Returns:

The data consolidators associated with this indicator if any

Return type:

ISet[IDataConsolidator]

property current

Gets the current state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Returns:

Gets the current state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Return type:

IndicatorDataPoint

property is_ready

Gets a flag indicating when this indicator is ready and fully initialized

Returns:

Gets a flag indicating when this indicator is ready and fully initialized

Return type:

bool

property item

Indexes the history windows, where index 0 is the most recent indicator value. If index is greater or equal than the current count, it returns null. If the index is greater or equal than the window size, it returns null and resizes the windows to i + 1.

Returns:

Indexes the history windows, where index 0 is the most recent indicator value. If index is greater or equal than the current count, it returns null. If the index is greater or equal than the window size, it returns null and resizes the windows to i + 1.

Return type:

IndicatorDataPoint

property name

Gets a name for this indicator

Returns:

Gets a name for this indicator

Return type:

str

property previous

Gets the previous state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Returns:

Gets the previous state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Return type:

IndicatorDataPoint

property samples

Gets the number of samples processed by this indicator

Returns:

Gets the number of samples processed by this indicator

Return type:

int

property signal

Gets the signal line for the TSI indicator

Returns:

Gets the signal line for the TSI indicator

Return type:

IndicatorBase[IndicatorDataPoint]

property warm_up_period

Required period, in data points, for the indicator to be ready and fully initialized.

Returns:

Required period, in data points, for the indicator to be ready and fully initialized.

Return type:

int

property window

A rolling window keeping a history of the indicator values of a given period

Returns:

A rolling window keeping a history of the indicator values of a given period

Return type:

RollingWindow[IndicatorDataPoint]

TrueStrengthIndex

class QuantConnect.Indicators.TrueStrengthIndex[source]

This indicator computes the True Strength Index (TSI). The True Strength Index is calculated as explained here: https://school.stockcharts.com/doku.php?id=technical_indicators:true_strength_index Briefly, the calculation has three steps: 1. Smooth the momentum and the absolute momentum by getting an EMA of them (typically of period 25) 2. Double smooth the momentum and the absolute momentum by getting an EMA of their EMA (typically of period 13) 3. The TSI formula itself: divide the double-smoothed momentum over the double-smoothed absolute momentum and multiply by 100 The signal is typically a 7-to-12-EMA of the TSI.

GetEnumerator()

Returns an enumerator that iterates through the history window.

Return type:

IEnumerator[IndicatorDataPoint]

Reset()

Resets this indicator to its initial state

ToDetailedString()

Provides a more detailed string of this indicator in the form of {Name} - {Value}

Return type:

String

Update(time, value)

Updates the state of this indicator with the given value and returns true if this indicator is ready, false otherwise

Parameters:
  • time (DateTime)
  • value (decimal)
Return type:

Boolean

Update(input)

Updates the state of this indicator with the given value and returns true if this indicator is ready, false otherwise

Parameters:
  • input (IBaseData)
Return type:

Boolean

property Consolidators

The data consolidators associated with this indicator if any

Returns:

The data consolidators associated with this indicator if any

Return type:

ISet<IDataConsolidator>

property Current

Gets the current state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Returns:

Gets the current state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Return type:

IndicatorDataPoint

property IsReady

Gets a flag indicating when this indicator is ready and fully initialized

Returns:

Gets a flag indicating when this indicator is ready and fully initialized

Return type:

bool

property Name

Gets a name for this indicator

Returns:

Gets a name for this indicator

Return type:

string

property Previous

Gets the previous state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Returns:

Gets the previous state of this indicator. If the state has not been updated then the time on the value will equal DateTime.MinValue.

Return type:

IndicatorDataPoint

property Samples

Gets the number of samples processed by this indicator

Returns:

Gets the number of samples processed by this indicator

Return type:

int

property Signal

Gets the signal line for the TSI indicator

Returns:

Gets the signal line for the TSI indicator

Return type:

IndicatorBase<IndicatorDataPoint>

property WarmUpPeriod

Required period, in data points, for the indicator to be ready and fully initialized.

Returns:

Required period, in data points, for the indicator to be ready and fully initialized.

Return type:

Int32

property Window

A rolling window keeping a history of the indicator values of a given period

Returns:

A rolling window keeping a history of the indicator values of a given period

Return type:

RollingWindow<IndicatorDataPoint>

property [System.Int32]

Indexes the history windows, where index 0 is the most recent indicator value. If index is greater or equal than the current count, it returns null. If the index is greater or equal than the window size, it returns null and resizes the windows to i + 1.

Returns:

Indexes the history windows, where index 0 is the most recent indicator value. If index is greater or equal than the current count, it returns null. If the index is greater or equal than the window size, it returns null and resizes the windows to i + 1.

Return type:

IndicatorDataPoint

Visualization

The following image shows plot values of selected properties of TrueStrengthIndex using the plotly library.

TrueStrengthIndex line plot.

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