Zynga Inc. announced its decision to check out of the real-money gaming market in the United States, prompting an 18.6% drop in shares on Friday morning.

Macquarie, one of the world's largest investment and fund management services provider, lowered its initial US$3 target for the Zynga stock to US$2.75. 

The gaming company also suffered a 40% loss in monthly active users for the second quarter and a drop in revenue of around 20%.

California-based games provider Zynga Inc launched its gambling series earlier this year in Britain but was unable to crack into the U.S. market due to legal issues. Gambling using real money remains illegal in many states in the country. Chief Executive Don Mattrick, who recently replaced founder Mark Pincus, warned on Thursday that the company may have up to a year of volatility ahead in his first official public statement since assuming the position. 

The current CEO also shared that he intends to bring the company "back to basics" with a renewed focus on free-to-play games for Android and Apple iOS and successful franchises such as "Farmville".