Quote from RiceRocket:
The 30 year treasuries are the most liquid instrument in the world. You can sell at any time with any size without a problem. The buyers of these are not holding to maturity, they're just riding along with the quantitative easing policy, or just parking cash in a safe instrument until the storm blows over. There's no problem holding them for 6 months if inflation is close to negative. You get 3% risk free. While the yield won't stay this low forever, it's a relatively safe investment if you have billions of dollars that need to be parked.
I know you are loving tooting up your position, but seriously, come on. 30 year = 3% risk free by holding them for 6 months? No. They are only risk free to maturity.
If you need to park billions of dollars, the 3-6 month part of the curve is the risk free part.
btw, the 30 yr buying hasn't even started yet. Just look at FOMC open market operations. Last operation was in late May 08.
