Sinhae Tonggong
On Chae Je-gong’s advice, Jeongjo abolished the licensed market merchants’ right to suppress unlicensed traders, except for the Six Licensed Stores; private trade expanded.

Yi Myeong-gi · Public domain · Source
In return for supplying the court, licensed shops on Jongno held the geumnanjeongwon — the right to shut down unlicensed traders. As the capital grew from the seventeenth century, their monopoly pushed up prices and hurt small traders. In 1791 (the sinhae year) the right was abolished for all but the Six Licensed Stores, opening trade to all.
Private merchants then flourished: the Gyeonggang merchants on the Han, the Song merchants of Gaeseong, the Man merchants of Uiju and the Nae merchants of Dongnae.
