Haruhiko Kuroda, the head of Japan's central bank (BOJ), surprised the market with an earlier-than-expected shift to the BOJ's policy of yield curve control (YCC). This has sent mini-shockwaves throughout the global bond market and those shockwaves are being amplified by thinner holiday week trading conditions.
The spike in US Treasury yields is resulting in a broken technical ceiling at 3.62%. The next line of defense is 3.76% before getting to a bigger picture pivot point like 3.84%. We may have seen 3.62% hold through the holidays if not for today's news. The better way to look at this week so far would be with yields exiting the downtrend that had been intact for the past month (yellow lines in the chart below). We expect some iteration of "sideways" between now and mid-January, at which point data and Fed-speak should help bonds shift into their next trend. Today's news simply widens the playing field for "sideways."