The stock market is a wealth-building powerhouse, and this year has been another one for the record books. Both the S&P 500 (SNPINDEX: ^GSPC) and the Dow Jones Industrial Average (DJINDICES: ^DJI) reached new all-time highs earlier in August, and the tech-heavy Nasdaq Composite (NASDAQINDEX: ^IXIC) has surged by close to 18% from its April low. Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first tim ...