Why the U.K.'s "trickle down" tax cut plan terrifies investors

Financial markets are in turmoil this week after the United Kingdom unveiled a series of historic tax cuts. The pound's value plunged, the International Monetary Fund urged the U.K. to reverse course and economist Larry Summers derided the move as "utterly irresponsible."

Although newly installed Prime Minister Liz Truss is betting that the tax cuts will spur economic growth and pull the U.K. out of a possible recession, the adverse market reaction suggests investors see the policy as a major mistake. Here's what's been announced and why investors are worried.