“…There has been some direct interest in the econometric literature, both theoretical and applied, on the use of functional data (e.g., Ramsay and Ramsey, 2002;Bugni, Hall, and Horowitz, 2009;Müller, Rituparna, and Stadtmüller, 2011;Bugni, 2012;Ferraty, Quintela-del-Río, and Vieu, 2012). Obvious examples of functional data in finance and economics are the yield curve, the implied volatility surface of derivative instruments, the volume weighted average price (VWAP), intradaily volatility processes, and many others.…”