JCPenney’s stock tumbled more than 8 percent to historic lows following The Post’s exclusive report that the retailer is hiking prices to make way for bigger-looking discounts.

Penney shares dipped as low as $5.69 — their lowest levels since the mid-1980s — before closing at $5.77, down nearly 8.3 percent.

The retailer in recent weeks has been raising its initial retail markups, especially in the jewelry department, so it could fatten the percentage markdowns beginning with a Valentine’s Day sale next month, sources said.

Penney is aiming to advertise discounts in the 40- to-60 percent range, versus discounts that had typically been in the 20-to-30 percent range the past year.

Chief Executive Mike Ullman is making the moves as he scrambles to repair damage done by his predecessor, Ron Johnson, a former Apple exec who wrecked the business by banning coupons and sales events in favor of everyday low prices.