Out of the Ordinary ETFs

Here are some out of the ordinary ETFs that might be a good measure of what is going on in the economy:

FLAT – if the yield curve is flattening
STPP – if the yield curve is steepening
CEW – emerging market currency fund
CCX – commodity currency fund
CPER – copper
STPZ – less than 5-year TIPS fund
LTPZ – 15 year plus TIPS fund
TTFS and PKW – buyback funds.