Relationships.
Among the important conceptual frameworks is how commodities, currencies, rates and equities interrelate.
This is the sea that alt-energy, cleantech/greentech swims in.
And it's something that the folks at Bespoke Investment Group do a good job with. For example:
Oil Closes at Record High (At Least in Dollar Terms)
Oil closed at a record high today even after news came out that OPEC would increase output. Part of the reason for oil's rise is based on the fact that it is priced in dollars which are falling. So even if global demand is unchanged, the falling dollar results in a higher price. When priced in Euros, oil is still 8% off its record high of 60.91 set on April 21, 2006.
They've been on a bit of a roll lately, Here are some recent posts:
Historical Dividend Yield of the S&P 500
Oil Up Eight Days in a Row
Oil Outperforming Oil Stocks
Oil Price Forecasts
