I reckon I have figured it out
** BID was the top performing stock on the ASX in 2018, up over 2000%
** So far in 2019 BID was only up 36% and it was past the middle of February, which I calculate would lead to just over 1000% for 2019 if continued at same rate
So clearly JB was waning in performing going at only half the rate of sp growth this year, and time to move him on.