“…The primary objective is to identify whether observable factors, such as trading volume (Dufour and Engle, 2000) and trading frequency (e.g., Engle and Russell, 1998), or unobservable factors, captured by distributions with progressively nesting properties, contribute more to trading intensity clustering (e.g., Kalaitzoglou and Ibrahim, 2013a). According to the empirical findings it is the observable factors that exhibit a higher explanatory power of the data generation process of trading intensity, suggesting that greater market transparency -the main objective of MiFID II -would ameliorate the predictive power of liquidity models and thus, it would contribute through liquidity to higher market efficiency (Kalaitzoglou and Ibrahim, 2015) and better price discovery (Medina et al 2014). 1 In more detail, the European Carbon market, known as the "European Union Greenhouse Gas Emission Trading System" (EU ETS), is the regulatory response of the European Union to the Kyoto Protocol (1997) and creates a new "commodity" market that has become the most important mechanism in reducing emissions.…”