RE:RE:RE:RE:SP - Was there some good news today? Or is this just a break
I just did some sleuthing and collected some data on this. I used D.un, ZEO (BMO O&G etf) and the tsx comp index.
Looking over the 2014 year, I found the following pattern:
D with ZEO
Jan-Jun: r = .09, p = .243
Jul-Sep: r = .54, p < .001
Sep-Dec, r = .77, p < .001
This pattern sort of replicates what you found. However, instead of a negative relationship between OG and D, I found no relationship. However, this is a significant positive correlation in more recent months. I'd have to look at longer term data to figure out this story a bit more. When doing a 5 year overall correlation, everything is positive for obvious reasons.
BUT when I additionally control for the TSX composite index (which I'm using as a marker for overall economical growth/inflation/etc as you suggest might be the cause of a relationship between D and the OG), I get the following pattern.
D with ZEO, controlling for tsx comp
Jan-Jun: r = .15, p = .057
Jul-Sep: r = .11, p = .275
Sep-Dec, r = .58, p < .001
For that period between Jul-Sep before the craziness with the OG sector, it seems that there was still no relationship between OG and D. My interpretation for this is that there was a lot of panic in the market for the last three months and people were behaving irrationally. Don't give the market too much credit. There shouldn't be a correlation, but there is. That sounds like panicked decision-making to me....and a good buy opportunity for many. :)
I think I'll be doing a lot more data mining in the future. Thanks for the inspiration! :)