I would assume that day to day movement in stock can be accurately compared with the Adjusted Close Price and not simply the Close Price, taking into account Stock Splits Dividends etc. http://www.investopedia.com/ask/answers/06/adjustedclosingprice.asp
Eg: For INFOSYS (INFY, NSE) https://in.finance.yahoo.com/q/hp?s=INFY.NS&a=11&b=12&c=2002&d=11&e=20&f=2014&g=d
The 2 day SMA (Simple Moving Average) on 19 Dec 2014 is (1998.65 + 1965.90) / 2 = 1982.275 Which is what Yahoo Finance is giving me.
But the 2 Day SMA on 2nd Dec 2014 Should be =
(Adj Closing on 1st Dec + Adj Closing on 2nd Dec ) / 2 = (1087.46 + 2126.60)/2 = 1606.73
But it is infact (According to Y! Finance)
(Closing on 1st Dec + Closing on 2nd Dec ) / 2 = (2174.93 + 2126.60)/2 = 2150.765
So the 2:1 Split has no effect on the SMA? I have taken the example of 2 Day SMA for easy calculation but my question is for general MACD, Bollinger Bands, EMA etc.
Many people seem to point to bugs with Yahoo's implementation. I thought given Yahoo's reputation, I thought this was too far fetched but this almost confirms it
Still one thing remains, should one adjust for these splits manually then for Technical Indicators? If not wouldn't it cause a skew in the results?