Though this year's record-beating stock rally continues to impress Wall Street, billionaire investor Bill Gross isn't so sure the bull market will maintain its hot pace for much longer. According to the so-called Bond King's latest note,

The biggest gains from the U.S. stock market’s record-setting bull run have likely already happened, according to billionaire “bond king” Bill Gross.

The rally that’s helped US stocks almost double in value over the past five years is tapering off, and investors should expect low but positive returns on their investments, according to Bill Gross.