May 7 (Reuters) - The following are the top stories in the Wall Street Journal. Reuters has not verified these stories and does not vouch for their accuracy.
* Federal Reserve Chairwoman Janet Yellen weighed in on a growing debate among investors and market economists, suggesting the yearslong stock rally may have driven prices too high and raising concerns that debt-market investors are taking excessive risks. (http://on.wsj.com/1ERpWBV)
* The U.S. Treasury Department said it plans to increase the supply of short-term debt, in a bid to ease investors' concerns about difficulty trading in global bond markets. (http://on.wsj.com/1IioYCT)
* Four big banks are expected to plead guilty to rigging foreign-currency exchange rates and pay billions in combined penalties as part of settlement agreements expected to be announced as early as next week, according to people familiar with the matter. (http://on.wsj.com/1coC8AS)
* Bill Gross's fledgling bond fund at Janus Capital Group Inc suffered large losses over the past week, undercutting a nascent comeback for the famed money manager who has yet to attract investors en masse at his new firm. (http://on.wsj.com/1ReSzzs)
* Cablevision Systems Corp Chief Executive James Dolan said he wants to consolidate the New York cable and broadband market, a proposal that would add a new dimension to the rampant talk of deals in the wake of Comcast Corp's failed purchase of Time Warner Cable Inc. (http://on.wsj.com/1IitvU6)
* Al Jazeera installed a new chief executive for its American news channel, Al Jazeera America, as it battles through business woes and internal controversies that have led some senior executives to leave in recent days. (http://on.wsj.com/1EbbZwc) (Compiled by Avik Das in Bengaluru)