The dramatic drop in gold prices has pushed other commodities lower, with silver plunging to a 2-1/2 year low Monday.

Silver is sinking for the same reason that gold has lost its luster, including a stronger dollar and low inflation, traders and analysts say.

Gold declined 8 percent in eight days—the longest losing streak since the 2008 financial crisis—to a session low of $1336.30 an ounce. Silver slid more than 3.5 percent to a session low of $20.25 an ounce, its lowest level since September 2010.

The big event this week is Wednesday, when U.S. Federal Reserve Chair Ben Bernanke testifies in front of the Joint Economic Committee, while the Fed releases the FOMC minutes to the April 30 and May 1 meeting.

The markets were all aflutter last week as John Williams from the San Francisco Fed (a dove) indicated he wanted to taper off purchases sooner rather than later.

But Bernanke is likely to reiterate exactly what he said at the May 1 meeting: that they are "prepared to increase or reduce" their bond purchases as the labor markets or inflation outlook changes.

(Read more: Bulls Will Be Driving Market, but Bernanke Is Steering)

Check out which companies are making headlines before the bell on Monday:

Campbell Soup — The food maker reported fiscal third quarter profit of 62 cents per share, excluding certain items, six cents above estimates, with revenues also beating consensus. It also raised its full year forecast. Campbell CEO Denise Morrison said the company was generally pleased with the quarter, though she expressed disappointment with the performance of certain units such as beverages.

Yahoo — Sources tell CNBC the company's board has approved a deal to buy blogging service Tumblr for $1.1 billion. Yahoo would not immediately confirm the deal, saying it does not comment on rumors or speculation, but does have a media event scheduled for later today.

Bullish momentum should drive stocks higher in the week ahead as markets watch to see if Federal Reserve Chairman Ben Bernanke weighs in on whether the economy is strong enough to justify paring back on Fed bond buying any time soon.

The debate about whether and when the Fed should start trimming back on its bond-buying program was underway in markets this past week, and was further fueled by the comments of Fed hawks. It also has made the Fed chairman's economic testimony before the Congressional Joint Economic Committee Wednesday even more important.

"He's got to be a bit of a two-handed economist," said Pimco strategist Tony Crescenzi. "On the one hand, he shows the Fed is concerned about downside risk to growth, and in so doing keeps markets believing the Fed will remain accommodative for a long time, but on the other hand, he has to seem somewhat optimistic about the future because the decision point is getting closer to a taper. Given the rising asset prices and improving employment…he'll say there's been progress."

Take a look at some of Friday's midday movers:

Tableau Software soared after its IPO. The data software company sold 8.2 million shares at $31 per share raising $254 million.

Visa hit a historic high after a Nomura analyst said the global payments firm justified a P/E multiple of 25-times earnings and raised his price target on the firm to $220 from $187 per share.

Check out which companies are making headlines before the bell on Friday.

Applied Materials: The semiconductor manufacturing equipment maker reported fiscal second-quarter profit excluding items of 16 cents per share, beating estimates by three cents. Revenue was also above consensus, with demand for smartphone chips helping offset a decline in personal computer sales.

Stocks head into Friday with a 1 percent gain for the week so far, but traders are increasingly seeing signs of wear, particularly as a growing list of disappointing economic reports stacks up against the market's gains.

Friday's data includes consumer sentiment at 9:55 a.m. ET, and leading indicators at 10 a.m.

(Watch Now: What Happens When Fed 'Tapers' Down)

Those reports follow on Thursday's Philadelphia Fed survey, weekly jobless claims, and housing starts, all disappointing in some way. Industrial production Wednesday and the Empire state survey were also weaker than expected. The Philadelphia Fed index fell from a positive 1.3 to a contraction of 5.2 in May. Weekly jobless claims increased by a surprising 32,000 to 360,000, and housing starts fell 16.5 percent to 853,000, but permits rose.

Check out which companies are making headlines after the bell Thursday:

Dell - The computer hardware and software company posted earnings of 21 cents a share, excluding one-time items, on sales of $14.07 billion, against expectations for 35 cents a share on sales of $13.50 billion. Shares were largely unchanged in extended-hours trading.

(Read More: Stocks End Lower on Fed's Comments; CSCO Up 13%)

JCPenney - The retailer posted a loss of $1.31 a share, excluding one-time items, on revenue of $2.64 billion, missing expectations for a loss of 89 cents a share on sales of $2.74 billion. And the company said first-quarter same-store sales fell 16.6 percent, as previously reported. Shares toggled in and out of positive territory in extended-hours trading.

If there is one lesson that resonates from years of watching markets, it's that earnings quality doesn't matter in cult stocks on the rise. Nobody wants to hear it. Look no further than Netflix. Or even Amazon.

All of which brings us to Tesla. Flying red flags over its earnings quality would appear to be foolhardy.

Still, to ignore it is just as foolhardy, especially given the first sentence of the most recent "shareholder letter" accompanying the fledgling car company's earnings. "Tesla reached profitability in the first quarter of 2013 for the first time in our ten year history," it stated.

Furthermore, lower in the same letter Tesla says: "We believe that the accepted automotive industry approach of focusing on margin improvement,profitability and deliveries are the more meaningful metrics for measuring progress."

If profits matter going forward, so does earnings quality. And according to Gradient Analytics, the earnings quality gets a grade of 'F."

What stands out the most?

"So many things," says Gradient research director Donn Vickrey."By declaring themselves profitable, I said there is just no way. How can this be at this point in the cycle? It has to be purely a paper profit and at that some elements of the paper may be lower quality than usual."

Paper or not, Vickrey believes whatever Tesla's profitability, it isn't sustainable.

Rather than go through all of his points, let's focus on just one: warranty accruals. This is the amount the company puts aside for expected warranty expenses — a non-cash charge that hits earnings as a cost of goods sold. The lower the provision, the less of a hit to earnings.

It's highly subjective, and Tesla current reserves at a rate,relative to sales, in-line with Ford and General Motors. But its warranty is longer than mainstream auto companies and "its product is based on new technology with unproven reliability," according to Gradient's report on Tesla." Of particular concern: The firm's eight-year, 100,000 mile battery warranty could prove to be extremely costly."

But what if the company is so new it simply doesn't know — so uses existing auto companies as a benchmark?

Under accounting rules, Vickrey says, if you don't know what they'll be "they should be higher, not lower."

Put another way: it could be yet another possible hit to earnings.

All in, Gradient estimates that once nonrecurring, unsustainable "and cosmetic" benefits are removed — rather than reporting a profit of $11.3 million, Tesla would've lost $91 million. And that doesn't include a more conservative warranty accrual. The good news, that's better than the $464 million it lost a year earlier — but not "profitable."

And we're not even talking about anything to support the current valuation.

My take: We've seen this before. Cult stocks like this run over any and all skeptics and critics — and Tesla is likely to continue leaving tire marks for the foreseeable future. Earnings quality, or lack thereof, rarely matters at this phase of a growth company's cycle. But Tesla makes such a big point of talking "profitability" that it should.

And what I know is this: investors may not care about earnings quality now, but one day it's likely they will wish they had. This has nothing to do with Tesla the car, and everything to do with Tesla's potential vulnerability with its stock.

P.S.: Tesla the stock is very dear to CEO Elon Musk. According to Tesla's proxy, his option grants are tied heavily to the company's market cap. Onward...

Beaten-down gold just can't find any love.

The metal bungee jumped Thursday—first to a sharply lower $1,368, then to a higher low in the mid-$1,380s—as the dollar sold off. Gold ended lower for a sixth day, at $1,386.90 an ounce, a decline of $9.30. But it could drop further, according to analysts.

"I'm not seeing any bargain hunters in there right now, and I don't see any reason why we won't test" test the April lows of $1,321, said Kevin Grady, president of Phoenix Futures and Options. "This is a bear market, and normal corrections are commonplace in bear markets," "The fact that gold rallies back $20 off the lows I don't think is signaling anything."