U.S. stocks continued their six-month climb into uncharted waters this week. The S&P 500 advanced another 2%, closing above 1,660 for the first time ever today. The Dow Jones Industrial Average nearly matched the benchmark index, tacking on another 250 points to close above 15,300.

As usual, several stocks advanced at an especially blistering pace. Here were five of this week’s biggest gainers:

• Cisco (NASDAQ: CSCO): +14%. Stronger-than-expected first-quarter earnings gave the chipmaker its biggest one-day gain since August 2011.

• Tesla (NASDAQ: TSLA): +13.5%. The electric car manufacturer is still getting a boost from its first-ever profitable quarter. The stock has now risen a whopping 160% in 2013 – with most of those gains coming in the past month.

• Groupon (NASDAQ: GRPN): +12%. Expectations had fallen so low for this daily deals site that even a unprofitable quarter managed to impress Wall Street. The company suffered a 1-cent-per-share loss last quarter, but the non-GAAP EPS of $0.03 gave shares a nice jolt.

• U.S. Air (NYSE: LCC): +7%. Last Friday’s approval of an American Airlines-U.S. Air merger pushed the stock to a 52-week high yesterday.

• Sony (NYSE: SNE): +11.5%. The struggling Japanese technology company had a big week thanks to Dan Loeb, a hedge fund manager who owns 6.5% of the company. Loeb vowed to spin off roughly one-fifth of Sony’s entertainment division into its own IPO, giving the stock a 10% bump on Tuesday.

David Tepper's Appaloosa Management released its 13F earlier and saw a slight increase in its value from $4.61billion to $4.71 billion.

(All units are in millions of shares)

Raised:

• Broadcom (NASDAQ: BRCM) from 3.42 to 3.62 • Celanese (NYSE: CE) from 0.65 to 1.05 • Ford