After jumping more than 32% in the previous period, the short interest in Frontier Communications Corp. (NASDAQ: FTR) added another 6.3% late in the month to more than 170.42 million shares, or 14.9% of the telecom's float. That was the greatest number of shares short since last August. The days to cover jumped to more than seven as the average daily volume shrank in the period. Some analysts see big upside in Frontier. The stock ended the short interest period more than 1% higher, compared to an almost 1% decline for the Nasdaq.