What's better than momentum? Mo' momentum. Let's take a closer look at five of this past week's biggest scorchers.

Company

Feb. 15

Weekly Gain

MEMC Electronic Materials (SUNEQ)

$5.34

19%

GT Advanced Tech (NASDAQ: GTAT)

$3.65

14%

Diamond Foods (DMND.DL)

$15.88

10%

Atmel (NASDAQ: ATML)

$7.17

10%

Groupon (GRPN 10.02%)

$5.98

10%

Source: Barron's.

MEMC Electronic Materials was a shining star after posting a better-than-expected profit on an adjusted basis. MEMC is a silicon wafer technologies pioneer.

GT Advanced Technologies apparently impressed investors and analysts at last week's 2013 Strategies in Light conference. The technology company with crystal growth equipment and solutions for the global solar, LED, and electronics industries was a presenter during the conference.

Diamond Foods was a nutty winner after an SEC filing revealed that BlackRock had acquired a nearly 7.9% stake in the snack maker.

Atmel bounced back last week after tumbling a week earlier on disappointing quarterly results. The maker of microcontrollers, capacitive touch solutions, and other components also made its own luck by announcing new solid-state lighting LED drivers that raise the bar in a few categories.

Finally, we have Groupon surging after a rare analyst upgrade. Shares of the daily-deals leader put in its biggest daily gain in more than two months after Stern Agee raised its rating on Groupon to "buy."