Bull Flattener

In a bull market, when long-term interest rates are falling more quickly than short-term rates, causing a flattening of the yield curve.

This often occurs during a bull market that's beginning to crest as investors shift their asset allocations from stocks (which are perceived as being overpriced) to long-term bonds, driving up bond prices (thus, driving down their yields).

The opposite can occur when an anvil falls on top of Wile E. Coyote, who is dressed like a bull and is charging at the Road Runner in a matador’s outfit.