I recently performed an experiment on Excel to determine whether or not stocks follow a random walk That is, the probability of a stock moving up or down each day, is 50/50. And its price is independent of where it was the previous day. *Note: This experiment was actually already done by Princeton and in the book A Random Walk Down Wall Street*

If this were true, it would mean that strategies such as Technical Analysis is an illusion. And that technical traders are Captain Hindsights.

To perform this experiment, I used the =RANDBETWEEN() function in Excel, to have it choose a number between 0 and 1.

0 = Tails

1 = Heads

Then I plotted each point on a chart. If a coin flip turned out heads, I would move up the chart 1 space. If tails, I would move down the chart 1 space.

You can easily perform this same experiment on your own using the same method.

## Coin Flip Test Run #1

In my first test run, I flipped a coin 88 times and produced the following results:

Immediately, we can see that a technical trader might consider a support level at the -4 area shown above from coin flip #13 to #38.

They might also say that this coin is “trading within a range” from -1 to -4 during that time.

At coin flip #41, it would have reached the resistance level at -1, and then break through to the top, until it hits resistance again at the +2 and +3 areas, before dropping back down.

## Coin Flip Test Run #2

I performed the same experiment again this time, using a million or so coin flips, to get a better sample size (actually, all I did was copy the columns and hit ctrl+D to see how far down the Excel worksheet it would go. This almost crashed my computer.)