If the rest of the world keeps piling into treasuries (as they are doing already), yields will probably continue to drop and market value of bonds you hold will rise, but do you really want to be holding treasury bonds if that doesn't materialize? The yield you'll get is miserable (1.4% on a 10 year) and you'd need to sell the bond at a loss to get out of it.
I don't buy treasuries directly, rather ETFs.
The question is how likely is this NOT to materialize?
There are TRILLIONS being poured into German, Japanese, Swiss and other bonds AT NEGATIVE RATES (which means the investor will get LESS than they paid, so getting 1.4% per year as well as your GUARANTEED principal in the world's reserve currency sounds MUCH better).
You have to realize who are the investors in these securities. They don't really have much choice. Insurance Companies, Banks, Governments, Pension Funds (and even mutual funds for some of their holdings). The demand outstrips supply. It's just not a balanced trade in my eyes. I think the upside (as in price appreciation - forget the yield) is much greater than the downside in the mid to long term. Short term - all asset classes are in for volatility.
The reason I bought into EUO just before the Brexit referendum was similar. I saw it as an
unbalanced trade. Bet makers and markets were expecting remain, so if that would be the outcome, I would say there's a 50/50 chance of sell on the news (which would benefit EUO) or mild positive cheer (as severe fundamental problems of the EU and the Eurozone don't go away if Britain remains), whereas a vote to Leave (as actually happened) would result in a rather sharp move down (I wanted to bet on the Pound, but didn't find a similar ETF, so I settled for betting against the Euro).
