first sale of the year; first trade of the year
Refers to the first business transaction of the new year, often in a celebratory or auspicious context. Similar to 初売り, but 初商い can emphasize the act of trading or the first deal itself.
See also: 初売り
I bought a lucky item at the first sale of the new year.
The shopping district is busy preparing for the first trade of the year.