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URL:  http://boards.fool.com/create-pri-daily-si-adjusted-price-30558539.aspx

Subject:  Re: YEY in GTR1 SI universe Date:  2/23/2013  6:37 PM
Author:  warrl Number:  241844 of 254157

Create [pri]: [daily SI-adjusted Price; share_lag=0 days; quote_lag=2 days]

It's been a while since I did anything with SI, so I can't say this is necessarily true of that data source...

... but on Yahoo, the adjusted price for the current day is always the same as the closing price, and prior days' adjusted price are relative to that.

Thus, the (Yahoo) adjusted price always contains information about the future. It's inherently a crystal ball and should never be used in backtests except via calculations that eliminate the crystal-ball aspect (e.g. checking for dividends/splits that occurred during a certain period, at or after the end of that period).
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