I thought I would chart the release of the Henry tax review and it's impact on the materials index in the standard way. I have marked in the release date, and the index levels. I note that the drop after the release before it rallied back up to the EMA 195, was identical to the drop prior to the release.
Every other equity and index which has back tested the EMA195 since I began charting with it has suffered a severe drop after a failed back test, but we could assume that this time it is different, and blame the review, in which case you could possibly attribute 54.6% of the decline to the reaction to the review, and discount all previous influences.
Given however that the rally up to the EMA195 and retrace is demonstrable not only in this case, but in the case of several hundred non-mining equities, I think you would be hard pushed proving a hypothesis that the two were linked.
Still if you choose your data points carefully, I am sure that the XMJ could be linked to a wide variety of political events
