“…It has also emerged in deep specifications such as in Ma, Shen, and Cottrell (2020). Fičura (2018) compares the ESN with HAR models in predicting stock market volatility of several indexes and finds that, on average, the HAR models perform better but also suggests that the ESN has a potential for being improved. Applications of ESN for stock price return forecasting are found in Zhang, Liang, and Chai (2013) and Dan et al (2014).…”