The Nasdaq Composite was an overachiever last week. After ending Friday higher — outperforming the S&P 500 and Dow Jones Industrial Average, both of which closed in the red — the tech-heavy index officially had five straight days of all-time closing highs.On a weekly basis, the Nasdaq Composite, with its 2% advance, also pulled ahead of the S&P 500's 1.6% increase and the Dow Jones Industrial Average's 1% rise.Given the Nasdaq Composite's moniker as the "tech-heavy index" (much favored by financial writers ...