It's unrealized gains of the ultrawealthy (nine-figure net worth and above). Still a bad idea, IMO, and extremely unlikely to happen for that reason. One huge asymmetry between the parties is that when a Democratic candidate proposes a bad idea, Democratic policy analysts (and, importantly, staffers) tell them it's a bad idea, and it gets MSM criticism, and it doesn't happen. When a Republican candidate proposes a bad idea (like huge regressive tax cuts, only partly offset by huge tariffs), there are no GOP analysts acting in good faith to say it's bad, and it just gets defended in the media that Republicans consume.