Minus sign in front of a value that corresponds to a certain text

[LFM]

Hello. I want to make a minus sign in front of a value in a column that corresponds to a text value in another column. Shown under I want make a "-" sign in front of all the numbers in lots when buy or sell is sell?

Like this:

Buy	2
Sell	-1
Sell	-3
Buy	2
Sell	-1

[dufoq3 · Accepted solution]

Hi @LFM, add as custom column:

if Text.Lower([Buy or Sell]) = "sell" then [Lots] * -1 else [Lots]

Whole code:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCnb18VHSUTJUitWJVnIKjQSyjcBsqIQpMscYSZUJEtsQWRFQeywA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [#"Buy or Sell" = _t, Lots = _t]),
    ChangedType = Table.TransformColumnTypes(Source,{{"Lots", type number}}),
    #"Ad_Lots +/-" = Table.AddColumn(ChangedType, "Lots +/-", each if Text.Lower([Buy or Sell]) = "sell" then [Lots] * -1 else [Lots], type number)
in
    #"Ad_Lots +/-"