I Have three fields, stock, date and sales. The stock in first date have a value (Initial stock), but I need that the value of stock in next row be the value of stock in the last row minus the value of sales of current row. Is possible update a field using previous register in Alteryx?
Yes: use their Multi-Row Formula tool, it allows exactly what you describe: your expression would look something like [stock] = [row-1:stock] - [sales]