Organisers hope that around £2.5million will exchange hands at the Kelso Ram Sales.
More than 5000 rams have been entered for sale.
It's the 175th year of the famous sales, organised by the Border Union Agricultural Society.
"It has just grown with tradition over all these years and it actually has become the barometer sale of commercial ram sales for possibly the whole of the UK. I always say to everyone I know they should always experience the ram sales once, it is unique."
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High pressure brings a mainly dry spell. Winds become lighter. Feeling warmer in any sunshine during Wednesday
The second of our special reports looks at the history of the Borders Railway - starting with the closure of the Waverley Line in 1969.
Predominantly dry over the coming few days with variable cloud & some sunshine. Cool nights but daytime temperatures recovering a little