Immediately Interact with Real-World Data
Mathematica allows dynamic interaction with continually updated real-world data, here the time series of the Dow Jones Industrial Average.
In[1]:=  |  Manipulate[
DateListPlot[
FinancialData["^DJI", DatePlus[DateList[], {-n, "Day"}]],
Joined -> True, Filling -> Bottom], {n, 30, 3000, 1}] |
Out[1]=  |