2018 - Flattening curve throughout the year with some slight inversion towards the end.
2019 - Complete inversion early in the year lasting awhile. Entire curve beginning to fall.
2020 - COVID Fed response slams the short end to the ground with the longer end having a pretty muted reaction.
2021 - Curve starts to stretch with short rates being extremely low and long rates showing pretty strong upside.
2021 - So far, the short rates have become unhooked from the 0 line and launched towards long rates. The curve has inverted again and there are no signs of slowing on the short end.