After years of an artificially undervalued Chinese yuan, most investors were shocked when it started falling against the dollar two weeks ago (David Einhorn shorted the yuan before it started falling, but it was a contrarian position). Now, many smaller investors may get caught in a position they assumed was almost risk-free. Unhedged, long CNY products popular with small/mid-sized investors “A more rapid decline could leave small/mid-sized corporate and private banking clients exposed to un-hedged positions (typically long CNH/short USD) via structured products,” write Citi analysts Ronit Ghose and Rahul Bajaj, who don’t think large banks are at risk because…