If you pull on a rubber band enough times, it’s eventually going to snap. The markets had been anticipating that the Federal Reserve would move swiftly to reignite the economy following another lackluster jobs report, and Ben Bernanke didn’t disappoint. Earlier this afternoon, the Fed outlined plans to purchase $40 billion in mortgage-backed securities on a monthly basis until the employment situation improves, and also noted that it’s unlikely its interest rate targets will move higher until mid-2015. News of this consistent bond-buying intervention sent all indexes screaming higher, with the S&P 500 (INDEX: ^GSPC) ending, once again, at multiyear highs, up 23.43 points (1.63%), to 1459.99.

Let’s take a glance at what stocks led today’s rally in the S&P 500, and note a few of the S&P 500’s laggards.

Companies that helped the S&P 500
Water-filtration company Pall (NYSE: PLL) picked a fantastic day to crush Wall Street’s fourth-quarter estimates. Although revenue for the quarter was essentially flat year over year, and net income fell 11%, both figures easily sailed past expectations -- revenue was $65 million higher than expected, EPS $0.22 better. However, in spite of its 7.9% gain, I’m not sure if I’d call this a slam dunk victory, as shrinking demand in Europe doesn’t bode well for its near-term growth prospects.

Anything and everything related to metals and mining also went on a tear today, with gold rising $34.50/oz., to $1,768.20/oz. Newmont Mining (NYSE: NEM) was one of those standouts, up more than 5%. The reason Newmont, and any miner for that matter, is rising, is often in response to a fall in the U.S. dollar which usually causes the underlying metals they produce to rise in value. Gold, silver, and copper are all way up today, which is leading this not-so-surprising rally across the board in metal miners.

Companies that hindered the S&P 500
UBS’ army of analysts willing to dish out downgrades took down another big name today in Northrup Grumman (NYSE: NOC). UBS analyst David Strauss slapped a dreaded "sell" rating on the company, noting that Northrup has significantly more exposure to a slowdown in government defense spending than its peers. Strauss also took exception to Northrup’s valuation, which he claimed is no longer at a discount to its peers. Northrup ended this bullish day down just over 1%.

Tyco International (NYSE: TYC) also fell victim to the downgrade bug, being downgraded to "equal weight" from "overweight" by Barclays, and having its price target reduced by $4 to $60. Tyco has suggested breaking itself up into three separate businesses -- ADT residential security, flow control, and commercial and fire security -- in order to improve operating efficiencies, and unlock shareholder value. The idea seems fantastic on paper, but Wall Street analysts are apparently growing impatient waiting for that breakup to occur.

Follow the yellow brick road?
This latest round of quantitative easing is almost assured to reinvigorate interest in mining stocks. Find out why gold could be a perfect fit for your portfolio, and why one tiny gold miner has gained the fancy of our analysts at Motley Fool Stock Advisor, by clicking here to download your copy of this latest special report.