Why did Protestant refugees move to Amsterdam after the fall of Antwerp?

Following the fall of Antwerp to Spanish forces in 1585, Protestant refugees migrated to Amsterdam primarily due to religious persecution and the collapse of the southern city's commercial dominance.

After capturing Antwerp, the Spanish governor-general, Alessandro Farnese, decreed that all Protestants must either convert to Catholicism or face exile. This ultimatum triggered a massive exodus of the population, with many seeking refuge in the northern [Netherlands].1

Simultaneously, the Dutch response to the fall of Antwerp involved blockading the Schelde River, which effectively severed the city's access to the sea and crippled its status as a major port. As a result, much of the trade and commercial activity previously concentrated in Antwerp shifted to Amsterdam. The arrival of these refugees, which included skilled Flemish merchants, significantly enriched Amsterdam's intellectual, cultural, and commercial life, fueling the city's rapid growth into a global trading metropolis.2