A simple query returns varying values. I assume Mathematica is pulling data from multiple data vendors and cycles through them, perhaps randomly.
Example:
1st Call:
FinancialData["bond", "Close", {{2015, 12, 31}, {2015, 12, 31}}]
{{{2015, 12, 31}, 102.52}}
8th Call:
FinancialData["bond", "Close", {{2015, 12, 31}, {2015, 12, 31}}]
{{{2015, 12, 31}, 102.703}}
10th Call:
FinancialData["bond", "Close", {{2015, 12, 31}, {2015, 12, 31}}]
{{{2015, 12, 31}, 102.52}}
If this is indeed how FinancialData works, one will never be able to achieve a repeatable result. Without repeatable results, this function is nearly useless for any sort of serious work.
Can anyone confirm that this is indeed what is going on here?