CPI (the Consumer Price Index) is arguably the most important data point for interest rates in a world where inflation is at the highest levels since the 80s and the Fed is not currently worried about the labor market (otherwise, NFP would still command more respect). Markets were concerned that this morning's release could be even hotter than forecasts suggested (granted, most of the year-over-year increase at the core level was expected due to "base effects").
As it happened, monthly CPI was right in line with forecasts and core CPI was 0.2 lower than forecast and previous. This is the 2nd time in a row it has moved lower after topping out most recently at 0.6% (down to 0.3% today). While the year-over-year chart might not look very hopeful, the monthly numbers are arguably more important in this environment, and they look much more toppy (or at least capable of being toppy if recent trends continue).
Bonds like it so far, with solid initial gains and some follow-through throughout the morning. The next test will be the afternoon's 10yr Treasury auction (probably not as big of a test as CPI, but still an opportunity to confirm or reject this post-CPI positivity.