The provided text does not contain an article about "c" or Wealthfront Advisers LLC boosting its stake in Citigroup. The content consists solely of a security verification message from marketbeat.com, indicating that the website is checking for malicious bots before allowing access. Specifically, the page displays a message to "Enable JavaScript and cookies to continue," along with a security service warning about malicious bot protection. There are no financial data, stock names, executive quotes, dates, or narrative details included in the source text provided. As the actual news article is not visible due to this verification screen, I cannot produce a summary containing specific numbers, names beyond those in the error message, or implications related to Wealthfront's investment activities or Citigroup's stock performance as requested by the prompt.