Since the Fed raised rates last week, yields in the Treasury market have surprised some market pros by heading lower — while the Fed and its outlook for more rate hikes this year are pointing higher.

Investors are hunkering down in the safety of bonds, and they are looking a lot less confident in the Trump economy than they did just a few months ago.

The move in yields is opposite to the one in bond prices, so that means investors are buying bonds, looking for security just when they should be feeling more upbeat about the economy.

What really has been a telling move, in addition to the sharp drop in rates, is the movement in one technical measure watched by bond pros — the "yield curve." In this case, the spread between the note yield and the 10-year yield, has narrowed or flattened, and gotten near levels it was at right around the election.

This means that longer-term debt is yielding much closer to short-term bonds. For instance, the current spread of 1.14 between the two is well below the 1.35 it was at in December, when the markets were convinced Trump policies would deliver hearty growth and stocks and risk assets would continue to rise.

Strategists say one of the reasons for this "flattening" move, often associated with economic softness, is uncertainty about the Trump agenda. This week's divide between Republicans over health care has highlighted that concern. Another factor is that the Fed is moving forward with at least two more interest rate hikes this year, and some central bank officials are looking for even more.