Important change as the TBT reverses ... I've been long the TLT (short interest rates) this way since September 2013 (!), but will now switch sides. When the ^TYX went briefly below 2.25% on 1/30/2015 (see bottom chart), that may have marked some kind of generational low ... time will tell (and I'm always happy to reverse position when prices dictate).
Long view of the long bond: