4.Yahoo!
  Headquarters: United States
 What is it known for:Web Portal,Search Engine,Yahoo! Mail
  Current Value: $19.5 billion
  Peak Value: $125 billion (2000)
  Percentage Residue: 15.6 percent
 Reason for downfall: Google Search, Gmail

Yahoo is estimated to have around 700 million visitors every month in more than 30 languages. Yahoo started in 1994 provided a directory for other websites organized as a hierarchy. Its acronym stands for “Yet Another Hierarchical Officious Oracle”.
Yahoo enjoyed its share in the market during the Dot com bubble in the late 90’s with its share prices topping the charts. However, it suffered through major setbacks since the Dot com bubble burst and has found itself a newly transformed approach.
But, no matter how hard Yahoo has tried to repeat its success and popularity among the masses it is a phenomenon that Google has captured majority of the market share that was once ruled by Yahoo. Google’s search engine is seen as the primary search engine by users and its email facility Gmail is one of the most widely popular email facilities in the market. Google has been successful in sweeping Yahoo’s market share and that has left Yahoo bruised. It has been adapting desperate measures to recuperate from the heavy losses and its revamping strategy is quite visible from the number of CEOs it has appointed in the past five years.
The recent discovery that more than 450,000 passwords of Yahoo users were compromised by hackers has served no good to the company further deteriorating its reputation in the market.