I want to chart the daily returns of a stock, and I'm using Yahoo finance data to download historic data. I was told to use Adjusted Close, but there seems to be an issue with this.
For ANTO.L, you can see that on 19 Jun 2006 there was a 5:1 split. The adjusted close reflected this, and went from 71.97 to 365.36. This of course skews my daily returns, as it represents a 400%+ return!
Should I be using adjusted close to calculate returns? It makes sense when considering dividends, but whenever there is a stock split there is then a huge skew. Is there something else I'm missing that I need to look into?
EDIT:
I think there's lots of examples of the same bad calculations. SRP.L shows the same for example. Problem is the Close is wrong, and the AdjClose is wrong, so I can't trust anything. Can anyone point me towards a good reliable free (or reasonably priced) provider of historic stock data, so I can use for comparisons?