So, I was curious about what happens when a stock is added to...

So, I was curious about what happens when a stock is added to the ASX300. I wanted to know if we should expect a surge in the share price due to index funds buying up. I'm a data kind of guy, so I downloaded the share price data of the seventeen stocks that were added to the ASX300 in September 2019 to check it out.

The following is a plot of the seventeen stocks that were added to the ASX300 in the Sept 2019 Rebalance. I have normalised them all at 22 Sept 2019 which was the day before the rebalance. What this tells me is that there is no clear trend. Some of the newly added stocks lost value and some of them gained value. The straight line from Oct onwards is ISX which has been suspended. The trend to pay attention to is the fact that most of these stocks were gaining value up to the rebalance (average gain of 20% in the months leading up to the rebalance). On average, after the rebalance, the trend is flat. I've got to admit, I didn't expect that.

For reference, the seventeen stocks in this analysis are:

	AD8	AQG	AVH	BGL	BUB	CDA	CIA	CNI	DTL	IAP	ISX	LIC	NIC	PET	SM1	WAF	Z1P