1. Chris Van Hollen says he will challenge Chuck Schumer for Senate majority leader  NPR
2. Van Hollen Says He Will Challenge Schumer for Senate Majority Leader  The New York Times
3. Schumer seeks to quash Democratic rebellion  The Hill
4. Chris Van Hollen launches bid to lead Democrats in US Senate  Al Jazeera
5. Chuck Schumer faces challenge for Senate leadership from rival Democrat  Financial Times

Source: Google Finance – Market News