Published by Jamie JemmesonAmid speculation that the US Federal Reserve will announce fresh quantitative easing later today, Morgan Stanley's David Greenlaw has suggested that the return on investment may be woeful.Speaking to the Telegraph, the analyst claimed that if Fed chairman Ben Bernanke votes to inject a further $2 trillion into the US economy (in addition to the $1.7 trillion already administered), growth will be around 0.3 per cent higher in 2011 and 0.4 per cent higher the following year.Unemployment will be down 0.3 per cent and 0.5 per cent over the two years, according to his calculations, while treasury yields will drop 50 basis points to 2.2 basis points."That looks like trivial returns for a colossal adventure into the unknown, with risks of dollar flight and mounting Chinese suspicions that the US intends to default on its external debts by debasement," speculated the Telegraph's international business editor Ambrose Evans-Pritchard.The dollar was on the defensive in global forex trading this morning, nearing a five-week low against a basket of currencies.For more information on foreign exchange treasury services and risk management, visit our Corporate FX site.