Hecte

Kyzikos was among the ancient world's most prolific producers of electrum coinage, and its hecte series circulated far beyond Mysia — recovered from hoards across the Black Sea littoral, the Aegean, and as far inland as Anatolia. The city's position on the Propontis made it a commercial hub, and its electrum fractions functioned as a trusted trading currency for roughly 150 years without any civic coinage reform interrupting the series.

The natural electrum used at Kyzikos carried a variable gold-to-silver ratio, which ancient merchants would have assessed by weight and by the familiar tunafish (tuna) backing mark struck on the reverse — a guarantor of Kyzikene origin rather than a fixed fineness standard.