I can't tell what the yield on ^TNX is!!! Or anything else.
3.13.18 What I do know is that the yield is wrong and the percentage change is wrong. Yahoo's summary page for ^tnx says the yield is 2.87%, down 0.02 or 0.52%. 0.52% works only if the yield is 2.852%. The interactive chart briefly showed 2.852% but reverted back to 2.85%. So you have a glitch, which would be remedied by making sure the yields on are ALWAYS quoted to three digits to the right of the decimal point.

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Charles Blaine commented
3:53 p.m. ET. The closing yield on ^TNX is still wrong. It should be 2.848%.NOT 2.85%. The interactive chart briefly shows the correct yield to make the math works and then morphs to the incorrect value. Why have you given up on going three places to the right of the decimal point?