NEW YORK ( ETF Expert) -- There are scores of erroneous beliefs that mislead the investing public. However, few are as dangerous to one's portfolio as the notion that economic growth correlates to stock market performance.Consider the inglorious ride for Chinese equities via SPDR S&P China ( GXC). In 2010, China's GDP growth rate topped 10%, while GXC managed a modest total return of 7.5%. The S&P 500 SPDR Trust ( SPY) garnered double-digit percentage gains in spite of sub-par GDP. In 2011, China's GDP still grew at a relatively robust 9.5%, but that didn't stop GXC from registering an abysmal -16.7%. Even with a disappointing total return of 2%, SPY outperformed without substantive economic growth to go with it. In 2012, GXC bounced back considerably, powering ahead with a total return of 23%. Not only was this better than SPY, but it occurred in spite of a troubling economic slowdown whereby GDP finished below 8%. Of course, most of the 2012 gains for GXC came on the heels of a three-month super-spurt. The manufacturing sector shifted from contraction to expansion, and has held firm over the last three readings. Moreover, after seven consecutive quarters of declining quarterly GDP rates, the fourth quarter of 2012 picked up considerably. Better yet, the Chinese economy is expected to recover and grow above 8% in 2013. The rocky road for Chinese stocks teaches us that stocks respond not to the growth rate itself, but the directionality, or the trend, of economic activity. China's economic growth rate drifted lower for several years with little stimulus by its banking authorities: 10% to 9% to 7.5% is far more troublesome for folks than a steady, but paltry 2%, in the United States.