Avis Budget Group Inc. shares continued their meteoric rise Tuesday, surging more than 15% in early trading to $700.51 as one of the most intense short squeezes in recent memory showed no signs of easing, with short interest exceeding 50% of the float and hedge funds scrambling to cover positions.

At 9:51 a.m. EDT, the stock had climbed $91.71, or 15.06%, extending a stunning run that has seen Avis Budget Group (NASDAQ: CAR) shares more than quintuple in the past month. The rental car operator, once trading near $100 in late March, hit intraday records above $600 on Monday and continued its parabolic advance amid heavy volume and retail frenzy.