> There is nothing to tax until they sell some shares.

That's tautological. I mean, it's true under current federal tax law. It's obviously not true under new California law, which is what the article is about.

Clearly the government can tax non-cash assets, and they do all the time. People act like "wealth taxes" are some moral horror or logical impossibility, while tossing their mortgage statement into a big file and pretending to ignore the property tax line on the escrow account.

Are there practical problems like "wealth has feet"? Sure. Taxation is hard and all systems can be gamed. But let's not pretend that there's a greater principle at work here.