[jiveturkey]

> None of this is an issue in the US, where you're only taxed when you sell.

Nope. In the US, you may be taxed when you exercise, and will be taxed again (against the new basis) when you sell. Whether or not you are taxed at exercise is a very complicated matter.

Keep in mind, when you are granted stock options, you don't actually have any equity. You have an /option/ to acquire equity. The taxable events are the acquisition of that equity and the subsequent liquidation of it.

[lazerwalker]

You’re totally right about options. I was thinking more explicitly about stock itself (e.g. RSUs in the case of employees at companies that issue those instead of options, or founder's stock in my personal case).

Separate from that, things are still more fraught in Germany: whatever your US taxation situation is, I'm not aware of any situation where a valuation change in stock/options/etc you're holding will trigger a taxable event for you, as I understand to be the case with Germany. As I understand equity taxation in the US, you'll only ever be taxed when events happen that you yourself have initiated (e.g. exercising options or selling stock).