Traders are heavily buying Treasury bond options, betting that the yield on the 10-year U.S. Treasury will rise to 4% in the coming weeks— a level not reached since late November last year.

This bullish bet comes at a time when U.S. Treasury yields have actually recently risen slightly, with the 10-year yield hitting a high of around 4.20% earlier this month, before fluctuating to 4.16% on Monday, as investors weigh the latest economic data and look for clues on the timing and magnitude of future rate cuts from Federal Reserve officials.

Data from the Chicago Mercantile Exchange (CME) released on Monday showed that there was a significant amount of buying in 10-year Treasury options contracts expiring in March over the past week. The total premium paid for this position has been exceptionally large, amounting to about $80 million, and the number of open contracts has surged to 171,153 contracts, a spike of 300% within a week.