Randomness is quite mysterious. If you are asked to generate 200 trials of heads and tails but you don't have a coin, then you can try making up fake data. But it is harder than you think, as there are some tests to detect aberrations from true data; most true data will have six heads or tails in a row.
In the same spirit, if you want to fake an arbitrary set of data, say the numbers on a balance sheet or the population of various district, there are patterns that true data satisfy, so be careful if you want to evade tax or fake a election victory.
By looking at the data of stock prices above, you may figure out what pattern we will explore(you may want to focus on the leading digit). For more details, check out this relatively interesting article or read this:
This work is made possible by NSF grant.