The magic system in Spinning Silver is not about power.

It's about conversion rates — and Miryem's entire arc turns on her ability to transform silver into gold, not through alchemy but through pure financial manipulation, understanding that value is contextual and that the same object means different things to different markets.

She becomes wealthy not by creating but by reading what each buyer will pay. This is not magic in the sense of breaking rules — this is magic as the ultimate capitalist operation: the recognition that everything, including yourself, has a liquidation price.

But Novik makes one category resistant to frictionless exchange: Jewish identity. When Miryem's father refuses to convert his practices to survive, he names the real cost of the fungibility fantasy — some conversions destroy the thing being converted. Yet the novel doesn't protect Jewish identity through isolation; instead, it shows characters continuously negotiating which parts can be traded and which cannot, which customs are portable and which are rooted. Maggie's transformation into a girl with power requires she temporarily abandon her own name, and Irina's survival requires she hide her faith. The magic system's obsessive inventory of conversions — one currency into another, one body into another, one name into another — reveals that under pressure, identity itself becomes just another asset class to be optimized.

The horror isn't that conversion is possible — the horror is that it becomes rational, and by the novel's end, survival has required every character to have made at least one trade they cannot undo.