Just to get out of ths result trauma… i m not sure abt ths concept in fixed income… assuming normal upward sloping yield curve… if 2 yrs rates rallied 9bps and 10 yrs rates rallied 7bps :- Bullish Steepener if 2 yrs rates backed up 9 bps and 10 yrs rates backed up 7 bps :- Bearish Flattener… but what if you rate rallied and other backed up… say for example 2 yrs rates rallied 5 bps and 10 yrs rate backed up 4 bps , we can say it is Steepener . but it is Bearish or Bullish? how do we make out that? pls enlighten me…
If memory serves (and this is where it’s difficult for me to separate what I know to be the case in practice vs. what CFAI teaches), the CFAI calls your second example a butterfly spread. Additionally, I don’t believe the CFAI references rates at all, but only uses CDS to put on these interest rate plays.