from pandas import DataFrame, Series def signals(data: DataFrame) -> Series: """ Generate swing trading signals based on the High Volume Days strategy. Returns a Series with 'L' for long signals and 'N' otherwise. """ data['200_MA'] = data['Close'].rolling(window = 200).mean() above_200_ma = data['Close'] > data['200_MA'] highest_volume = data['Volume'] == data['Volume'].rolling(window = 5).max() close_lower_than_open = data['Close'] < data['Open'] signal_condition = above_200_ma & highest_volume & close_lower_than_open signals = signal_condition.apply(lambda condition: 'L' if condition else 'N') return signals