We can use these characteristics and our dataset of bond performance during equity bear markets to run a what - if analysis on possible outcomes. (hussman.net)
It can be estimated as a backward - looking quantity by observing stock market and government bond performance over a defined period of time, for example from 1970 to the present. (investopedia.com)
We've had an unusually long run of good bond performance, but this is unusual. (canadiancapitalist.com)