Tax worries have hurt stocks, especially tech

The details of the Republican tax bill are what matter at the moment. In a final push for funds, a provision was added to include a corporate alternative minimum tax that would set the floor on taxes at 20%.

Previously, companies could lower their burden by investing in things like R&D.

The thinking was that in all the haste to get a bill through the Senate, it was a mistake. That's looking more like it's the case.