What commodity created the speculative bubble in the netherlands during the 1630s?

Tulips

Explanation:

Tulips were brought to the Netherlands in the late 1500s from their native Turkey.

At the time, the Netherlands was one of the most developed regions in Europe, with many wealthy merchants and tradesmen who found tulips very appealing.

Soon, a tulip boom ensued in the Netherlands. It was almost customary for rich Dutch people to own a collection of tulips.

This inflated the prices, creating an economic bubble. The bubble finally bursted in 1637, when most buyers declared that they could not pay the inflated prices anymore.