Hi Larry,
AI uses the adjusted close in its calculations.
The way AI works when you ask it for monthly data is to use the start date you selected and retrieve the daily data. Then it jumps ahead one month, retrieves the daily data on that day and repeats the process until the end date is reached.
So AI is actually always using daily data, but ignoring the data items between months. That's why you see 75.60 as the price for 9/3/2002.
The daily data are the most accurate and that's why AI uses them.
Here's a description of the differences from Yahoo's help page...
• Daily Historical Quotes provide you with the daily open, high, low, close, and volume for each trading day in the chosen date range.
• Weekly Historical Quotes retrieve the open trade from the first trading day for the week, the high and low price quotes of the week, and the closing price on the last trading day of the week. The weekly volume is the average daily volume for all trading days in the reported week.
• Monthly Historical Quotes report the open trade from the first trading day of the month, the high and low price quotes for the month, and the closing price on the last trading day of the month. The monthly volume is the average daily volume for all trading days in the reported month.
Let me know if you have any other questions.
Thanks,
Mark.