Although FinancialData gives the correct result for the current stock price:

In[49]:= FinancialData["GS"]

Out[49]= 190.002

If (at least as of today), one asks for historical data the results are completely wrong. E.g.:

In[50]:= FinancialData["GS", {{2014, 11, 10}, Today}]

Out[50]= {{{2014, 11, 10}, 25.58}, {{2014, 11, 11}, 
 25.58}, {{2014, 11, 12}, 25.63}, {{2014, 11, 13}, 25.68}}

Note that Wolfram|Alpha gives a correct time series graph, and the Yahoo site (which is the API that FinancialData uses) gives the correct values.