Barracuda, Gap, Zillow, Dover and American Airlines are big market movers

Stocks that moved substantially or traded heavily Friday on the New York Stock Exchange and the Nasdaq Stock Market:

NYSE

Barracuda Networks Inc. (CUDA), down $7.57 to $31.55

The cloud-based security and storage services provider didn't sign as many large and lengthy storage deals in the first quarter.

Gannet Co. (GCI), up $1.31 to $13.37

Activist investor Carl Icahn increased his stake in the newspaper and publishing company from 6 percent to 6.5 percent.

Dover Corp. (DOV), down $1.96 to $65.28

The industrial equipment company cut its full-year profit forecast, citing lower demand in the North American energy market.

Gap Inc. (GPS), down 20 cents to $37.58

The retailer reported flat June same-store sales, which were held down by lackluster results from its namesake brand.

Nasdaq

Zillow Group Inc. (Z), down $6.59 to $78.67

The real estate marketplace company's chief financial officer resigned as it continues its integration with former rival Trulia.

Helen of Troy Ltd. (HELE), down $10.37 to $86.71

The personal and household products company reported a fiscal third-quarter financial results that disappointed Wall Street.

American Airlines Group Inc. (AAL), up $1.54 to $41.21

The airline reported growth in June of passenger traffic, which is a key measure, and reaffirmed its outlook for passenger revenue.

Baidu Inc. (BIDU), up 18 cents to $187.75

The Internet search services company's stock rose as efforts by China to stop a rout in the stock market met with some success.