IT’S a ho-hum economy, at best. Four years after the end of the Great Recession, gross domestic product appears to be growing at a lackluster pace, labor productivity is lagging and, despite a slight improvement last month, the unemployment rate is still a painfully high 7.5 percent.

Yet in the financial markets, it’s a much happier world. An epic rally in stocks has been roaring ahead, with the Dow Jones industrial average on Friday briefly surpassing 15,000 for the first time.

Thanks to the intervention of the Federal Reserve, the bond market remains improbably strong, too. The benchmark 10-year Treasury rate fell as low as 1.612 percent last week, driving prices, which move in the opposite direction, to stratospheric levels. That helped Apple sell $17 billion of bonds at yields once reserved for the sovereign debt of only the safest governments.

In short, it’s been a giddy time to be an investor. But while the financial markets are soaring, the real economy appears to be mired in an endless slog. That discrepancy raises a troubling question: How long can financial portfolios continue to swell if wages, employment and corporate revenue remain constrained?