Bill Gross, manager of the world’s largest bond fund at Pimco, said Wednesday that income, rather than capital gains, would drive future investment returns. “Capital gains from almost all asset classes are approaching dusk,” Gross said in his latest monthly letter to investors. “Low but relatively dependable income will be the market’s future driver.” Income is characterized as the interest payout on an asset, whereas capital gains are known to be the price gains on an asset.