First the facts: ITC Holdings has approved a 3 for 1 stock split in the form of a stock dividend. On February 28, shareholders of record as of February 18 will receive a distribution of two additional shares of ITC common stock for each share they hold. Upon completion of the stock split, ITC will have approximately 157.5M shares of common stock outstanding. The company approved a quarterly cash dividend on ITC's common stock of 14.25c per share on a post-split basis payable on March 19 to shareholders of record on March 10.

Now to your question. The historical prices in Yahoo Finance only report the actual prices paid for that stock on any particular trading day. They are NOT adjusted down backwards from the day of a stock split. But you will also note that YF reports a closing price for ITC of $102.60 on Feb. 28 and then on the next line shows the 3:1 stock split and sure enough those shares are starting to trade at about 1/3 the value of Feb. 28. However, the last column in that table show the adjusted stock price which is an adjusted number based on any stock splits and dividends paid and therefore informs you of that stock split.

http://finance.yahoo.com/q/hp?s=ITC+Hist...

I thought historical data was adjusted for both splits and dividends. However, I see, for example, that ITC is not adjusted for a recent 3:1 split. Have other uses seen this problem in other symbols?