Need a formula for min with this data

[Nishant79]

Hi i have a cell B2 which has a data which is live and keeps on changing continuously now on A2 i want to capture the lowest number that B2 has made though out the day. Like if B2 moves from 10 to 15 then A2 should keep showing me 10 until B2 comes below 10 then A2 should show me the lowest that B2 have made .

But just to inform you that the cell B2 data is on a live data and keep changing continuously every second.