The given code represents a trading strategy based on Bollinger Bands and the Relative Strength Index (RSI). Here's a description of what the strategy does:
The strategy consists of two main functions: populate_indicators and populate_buy_trend (for generating buy signals) and populate_sell_trend (for generating sell signals). These functions are part of a class called Bb which implements the IStrategy interface.
In the populate_indicators function, various Bollinger Bands are calculated using the qtpylib library and added as columns to the input dataframe.
Bollinger Bands are volatility bands placed above and below a moving average.
In this strategy, Bollinger Bands with standard deviations of 1, 2, 3, and 4 are calculated and stored in different columns. The populate_buy_trend function generates buy signals based on certain conditions. First, if enabled, it checks if the RSI value is below a specified threshold. Then, based on the value of buy_bb_value, it compares the closing price of the asset with the lower band of the corresponding Bollinger Band. If the conditions are met, a 'buy' signal is indicated by setting the 'buy' column to 1 in the dataframe. Similarly, the populate_sell_trend function generates sell signals. If enabled, it checks if the RSI value is above a specified threshold. Then, based on the value of sell_bb_value, it compares the closing price of the asset with the lower, middle, or upper band of the corresponding Bollinger Band. If the conditions are met, a 'sell' signal is indicated by setting the 'sell' column to 1 in the dataframe. Overall, this strategy combines Bollinger Bands and RSI to generate buy and sell signals based on the specified conditions and indicators.