negative bond duration

[zdreg]

The effective duration of his fund somehow fell to minus 4.58 years at one point, even though the prospectus on Janus’s website says the “fund’s
https://www.bloomberg.com/opinion/a...y-tale-for-any-future-bond-kings?srnd=premium

please explain now this is possible.

 

[srinir]

Possibly, he was short treasuries.

Also he is well known to juice his returns by selling calls. Probably he overwrites his call options and market rallied, effectively became short.