1 Masa Sumatra

The masa was the standard silver trading unit across the Malay-Indonesian world during the height of maritime commerce through the Malacca Strait, when Sumatran ports functioned as critical nodes between Indian Ocean and South China Sea trade networks. These small dumps — crudely shaped rather than struck to any die — circulated alongside imported Chinese cash and Indian gold in a monetarily plural economy that no single polity controlled.

Attribution to specific kingdoms remains contested; the HCM grouping covers pieces associated with several northeastern Sumatran coastal polities active before Islamization reshaped the region's political geography after roughly 1300.