Rick Rieder, a top investing official at the world's biggest asset manager, BlackRock, says earnings growth forecasts and cash being redeployed into the market continue to support a bullish thesis for stocks. "I don't think we've ever seen anything like this," Rieder, who oversees over $2 trillion in assets across bonds and stocks, tells Scott Wapner at the CNBC CEO Council Summit in Washington, D.C.