Friday led to record gains for the stock market, as the S&P 500 closed at an all-time record. Investors remain upbeat about the prospects for economic growth in the U.S. and around the world, and they largely dismissed concerns about Russian President Vladimir Putin's comments concerning Ukraine as political posturing. Even though the broader market posted reasonable gains today, the truly impressive moves came from a select group of stocks, with Hewlett-Packard (NYSE:HPQ), Renewable Energy Group (NASDAQ:REGI), and GT Advanced Technologies (NASDAQ: GTAT) among the best performers Friday.

Hewlett-Packard gained 6% after reporting its fiscal second-quarter earnings yesterday afternoon. Revenue fell 1% from the year-ago quarter, but earnings met expectations, and the tech giant said that it would reduce its labor force by another 11,000 to 16,000 jobs. Given that Hewlett-Packard had already planned for a massive job reduction of 34,000 just two years ago, the move shows the extent to which CEO Meg Whitman is willing to go to keep costs under control in a falling-revenue environment. At least for now, shareholders are interpreting the move as positive for earnings; but some worry that Hewlett-Packard is following a course that many other companies have seen as unfruitful in the long run.

Renewable Energy Group jumped 11%. The biodiesel producer announced earlier this week that it would fully acquire Dynamic Fuels, a privately held joint venture in which meat producer Tyson Foods currently holds a 50% interest. In combination with an earlier move to acquire Syntroleum, which owns the other 50% of Dynamic Fuels, Renewable Energy Group's deal with Tyson will involve cash and repayment of debt of about $30 million, with possible earn-out payments of as much as $35 million depending on production at the biorefinery plant that Dynamic Fuels owns. Today's move suggests that it took some time for analysts to get comfortable with the deal, which should increase Renewable Energy Group's output capacity by almost 30%.

Source; GT Advanced Technologies.

GT Advanced Technologies rose 8% after reports that smartphone producers Samsung and LG would add covers made out of sapphire material to their mobile offerings. GT Advanced Technologies is a major producer of sapphire, which has attractive durability characteristics. Until now, the general objection to sapphire has been cost-related, as other materials, like Gorilla Glass, are far less expensive. But with the prospects of seeing greater use of sapphire in mass-produced mobile devices, GT Advanced Technologies and its peers appear to be making inroads toward gaining greater acceptance in the mobile arena.