Monday Morning Market Movers: Lumber Liquidators Holdings Inc. Off 24%

Lumber Liquidators Holdings Inc.

shares fell more than 24 percent before trading got halted at about 9:30 a.m. Eastern time Monday on pending news. Shares were hurt by a report on "60 Minutes" that its flooring flunked formaldehyde tests. Visa Inc.

gained more than 4 percent Monday after Costco Wholesale Corp.

chose Visa and Citigroup Inc.

as its new credit card partners. Costco is set to terminate an exclusive agreement with American Express Co.

next year. NXP Semiconductors NV

gained 13 percent on news the company will acquire Freescale Semiconductor Ltd.

for cash and stock worth $13.14. Freescale gained nearly 10 percent, trading recently at $39.67. Mavenir Systems Inc.

, a network software company, jumped nearly 18 percent, Monday, trading at $17.19, after Mitel Networks Corp.

agreed to acquire the company in a cash and stock deal valued at $17.94. Mitel traded down more than 7 percent to $9.41 recently. GrafTech International Ltd.

increased 15 percent after the graphite materials supplier beat fourth-quarter expectations. Clean Energy Fuels Corp.

fell nearly 6 percent in Monday morning trading after Raymond James reiterated an Underperform rating on the shares. The provider of natural gas for automotive fuel had gained sharply on Friday after beating quarterly earnings expectations.