will make this thing go down? Rates go down, it goes up, rates go up, it goes up. I guess when the yield comes down to around 6% it will stall out but there's lots of upside before then. Surely if we see a repeat of last fall when all faith was lost in corporate America, it will take a dive. Other than that this thing is like owning the safest, giant interest bearing savings account you could imagine.JMHO