Frontier Communications Corp. had the greatest drop in short interest relative to shares outstanding among Kagan-covered communications companies between July 14 and July 31.

The percentage of the company's shares held short relative to shares outstanding dropped 224 basis points to 30.05% as of July 31. The company also topped the list of most shorted communications companies during the second half of July.

IDT Corp. posted the biggest increase in short interest relative to shares outstanding among Kagan-covered communications companies between July 14 and July 31. The percentage of the company's shares held short relative to shares outstanding rose 94 basis points to 4.71% as of July 31.