The most concrete portion of the plan would be slashing the corporate tax rate to 15% from its current top rate of 35%, and let "pass-through" companies like Trump's be taxed at the same rate (the current top rate is 39.6%). That'd deliver huge savings to corporations. The plan also promises to let companies bring back money that's been stuck overseas at a "one-time tax" rate, and while that lacks specifics it could be a boon to multinational corporations.