Stocks making the biggest moves after hours: Dave & Buster’s, Medidata, and more

Check out the companies making headlines after the bell:

Shares of entertainment and restaurant company Dave & Buster’s fell 17.6% during extended trading after missing earnings and revenues estimates and lowering guidance for the fiscal year. The company reported earnings of $1.13 per share on $364 million in revenue for its first quarter, falling short of the earnings of $1.14 per share on $372 million in revenue expected by analysts polled by Refinitiv.

Dave & Buster’s also lowered full-year revenue guidance, saying it now expects revenue between $1.365 billion and $1.39 billion. It previously forecast revenue between $1.37 billion and $1.4 billion. The Refinitiv consensus estimate for full-year revenue was $1.399 billion.

French company Dassault Systèmes is nearing a deal to buy Medidata Solutions, a software company focused on clinical trials, people familiar with the matter confirmed to CNBC. Shares of Medidata rose about 5.5%.

Shares of Raytheon and United Technologies held mostly steady after activist investor Bill Ackman came out against the proposed merger between the two companies. United gained about 0.8%, while Raytheon was unchanged.