In this effort, we have focused on the former peaks from the 2007 to 2008 glory days, if applicable. The run higher seems like a bubble, but you will see that the bubble of today is nothing compared to the bubble of 2007 and 2008, when energy and alternative energy were flying high.

24/7 Wall St. evaluated the likes of First Solar Inc. (NASDAQ: FSLR), SunPower Corp. (NASDAQ: SPWR), MEMC Electronic Materials Inc. (NYSE: WFR), GT Advanced Technologies Inc. (NASDAQ: GTAT) and SolarCity Corp. (NASDAQ: SCTY) in the stock coverage. We also wanted to highlight exchange traded fund (ETF) performance and historical data on the Guggenheim Solar (NYSEMKT: TAN) and PowerShares WilderHill Clean Energy (NYSEMKT: PBW).

First Solar Inc. (NASDAQ: FSLR) is the de facto solar leader, and its shares have done what seemed nearly impossible just a few months ago. This stock went from less than $30 from late in 2006 after its initial public offering (IPO) to more than $300 in mid-2008 at the peak of the energy craze. Then came the “heads I win, tails you lose” trading, in which First Solar lost literally half of its value from July 2008 to December 2008. By June 0f 2012, First Solar shares were at a low even under $12, and the stock closed out 2012 at $30.86. Now we have shares up around $56, implying year-to-date gains of 81% and gains from last June’s lows of nearly 400%.

SunPower Corp. (NASDAQ: SPWR) remains a miracle recovery, but we question why on earth Total S.A. (NYSE: TOT) has not acquired the rest of the company when the stock was less than $5. It is the largest holder by far, and it could have taken this outfit over on the cheap. This stock trades around $21.60, after a drop of more than 4% on Tuesday, but shares hit a high of $23.76. SunPower shares peaked at more than $100 in 2007 and again in 2008.

MEMC Electronic Materials Inc. (NYSE: WFR) has been the less-followed winner for its solar materials making, but its rise has been massive as well. After hitting a low of $1.44 in the past year, the stock closed out 2012 at $3.21. With shares around $6.70 now, this is a gain of close to 400% from the lows, and a gain of more than 100% so far in 2013. Keep in mind that MEMC peaked at $96 in late 2007, and this was a $17 stock by the end of 2008.

GT Advanced Technologies Inc. (NASDAQ: GTAT) shares are back up to $4.60, but we would caution that this one came public as one of the last solar players out there in late 2008. It makes equipment for solar panel makers and providers, and it does not fit the same historic pattern as it missed much of the 2007 and 2008 silliness. This stock is up 75% from its low of $2.61 from March 4, 2013. GT is also up just over 50% from its closing price of $3.03 in 2012.

If you want to see just how fast a good thing can come to a crashing end … SolarCity Corp. (NASDAQ: SCTY) is supposed to be the new kid on the block, and its shares hit a new all-time high of $52.77 just on Monday. After a double-digit drop, this one is back to $45. Do not feel too bad for those shareholders because, even after this last sudden drop, we have this 2012 IPO up a whopping 275% or so year-to-date from the $11.93 close for 2012.

The Guggenheim Solar (NYSEMKT: TAN) ETF is solar-focused and is still up 1.9% at $26.04 so far on Tuesday, but that is down from a high of $27.87 earlier in the day and up from a 52-week low of $12.60. Even after pulling back from the highs, this ETF is up a whopping 64% year-to-date from the closing price of $15.64 at the end of 2012. Trading volume has been elevated, and even exponentially higher of late. A reverse split has clouded the comparisons back to 2008 when this ETF was created.

There is also the PowerShares WilderHill Clean Energy (NYSEMKT: PBW) ETF, which has a more diversified angle of alternative energy, cleaner energy and conservation, rather than just being solar. This one just hit a new high of $5.87 for the year and shares are up less than 1% at $5.67 as of last look. Even after the pullback, this is up almost 38% year-to-date from the $4.08 close at the end of 2012. Keep in mind that this ETF was above $28 at the peak back to late 2007 and in 2008, but by the end of 2008 it back to less than $10 per share.

If this sounds as though we have the pom-poms out cheering on the solar rally, we actually want investors to consider the risks more than just chasing the gainers. Our first point to make is that when you see articles of this magnitude cheering a great recovery, then perhaps the easy money has already been made. If you want proof of how volatile and wild price moves are expected, an at the money straddle or spread using the June-2013 $55 strike prices in puts and calls would cost you about $8.25 if you tally up both prices. That implies that the stock would have to rise to above $63 or fall to under $47 before the bets pay off.

The solar sector moves have been impressive. Make that more than impressive. The problem is that we are in a different valuation world now compared to the bubbles of the past. The partial austerity-driven, tax-credit-expiration world we live in now and the tariffs (trade wars) have changed the landscape to the point that it seems almost incomprehensible that the old bubble days of 2007 and 2008 could return. Some of these companies will continue to go on to do great things in the years ahead. Other solar players may fade into the history books, even after we have seen many bankruptcies in this sector.

Some longer term questions remain. Will solar companies get to form master limited partnerships? Will they become utilities? Is a market cap of almost $5 billion for First Solar crazy, or is it cheap compared to 2007 and 2008? Is Solar City’s $3.5 billion market cap valuing it as the utility of the future? Is much of the volume being driven by short covering? Or is the volume being driven by ETFs influencing the sector?

Another pure-play solar energy installer, SolarCity Corp. (NASDAQ: SCTY) has also posted a new 52-week high this morning. Like Real Goods, SolarCity put up quarterly results that included a larger net loss than in the same quarter a year ago. SolarCity managed to snag more revenue than it did a year ago, but that mark eluded Real Goods, which saw an 8% drop in year-over-year revenues.

Real Goods has signed a deal with homebuilder Lennar Corp. (NYSE: LEN) to install solar PV at some of the homebuilder’s new communities in California, with a potential to expand to other areas of the country.

Both Real Goods and SolarCity operate exclusively in the U.S., so neither is taking advantage of the expanding solar market in Japan. SolarCity and Real Goods both offer solar PV systems that have no upfront cost for home and business owners willing to sign a 20-year power purchase agreement.

Other than the fact that Real Goods has remained in the background since is IPO 10 years ago this month, there’s really not an awful lot of news or data to warrant such a steep, quick jump in the share price. But installation of solar energy is where the profits will be for the near term. SunPower Corp. (NASDAQ: SPWR), First Solar Inc. (NASDAQ: FSLR), and MEMC Electronic Materials Inc. (NYSE: WFR) all have installation operations as well, so there is stiff competition from large firms to say nothing of local installers. But it’s where the money is right now, and with stabilizing prices for solar modules, margins and profits could be about to get better.

The U.S. dollar index is trading down 0.28% today, now at 83.5980. The GSCI commodity index is down 0.1% at 624.91. WTI crude oil closed up 0.9%, at $95.16 a barrel. Brent crude trades up 0.2% at $103.93 a barrel. Natural gas is down 3.3% today at about $3.94 per million BTUs following a larger-than-expected addition to U.S. inventories<<LINK>>. Gold settled down 0.7% today at $1,386.90.

The unofficial closing bells put the DJIA down more than 42 points to 15,233.22 (-0.28%), the NASDAQ fell more than 6 points (-0.18%) to 3,465.24, and the S&P 500 fell 0.50% or more than 8 points to 1,650.47.

There were a several analyst upgrades and downgrades today, including:

• Barrick Gold Corp (NYSE: ABX) was cut to ‘underperform’ at Macquarie;
• Chesapeake Energy Corp. (NYSE: CHK) cut to ‘neutral’ with a $20 price target at J.P. Morgan;
• Constellation Brands Inc. (NYSE: STZ) raised to ‘buy’ with a price target of $64 at Stifel Nicolaus;
• Palo Alto Networks Inc. (NYSE: PANW) raised to ‘overweight’ with a price target of $65 at Morgan Stanley; and
• SunPower Corp. (NASDAQ: SPWR) raised to ‘outperform’ at Cowen Securities.

Earnings reports since markets closed last night have resulted in some price changes for reporting companies as of the last half hour of trading today:

• Dillard’s Inc. (NYSE: DDS) is up 2.6% at $91.36 after posting a new 52-week high of $92.93 earlier today;
• Jack in the Box Inc. (NASDAQ: JACK) is down 4.1% at $36.78;
• Skechers USA Inc. (NYSE: SKX) is down 3.6% at $20.64;
• E Commerce China Dangdang Inc. (NYSE: DANG) is up 5.3% at $5.20;
• Kohl’s Corp. (NYSE: KSS) is up 4.6% at $51.97;
• ReneSola Ltd. (NYSE: SOL) is down 14.5% at $1.89; and
• Wal-Mart Stores Inc. (NYSE: WMT) is down 2.1% at $78.21.

Before markets open tomorrow morning we are scheduled to hear earnings from Autodesk Inc. (NASDAQ: ADSK), Dell Inc. (NASDAQ: DELL), J.C. Penney Co. Inc. (NYSE: JCP), Nordstrom Inc. (NYSE: JWN), and Stage Stores Inc. (NYSE: SSI).

Some standouts among heavily traded stocks today include:

Cisco Systems Inc. (NASDAQ: CSCO) is up 13.1% at $23.98, after posting a new 52-week high of $24.24 earlier today. The networking equipment giant posted strong earnings last night.

National Bank of Greece SA (NYSE: NBG) is up 20.1% at $2.03. The Greek bank’s shares have risen by a third since the country’s sovereign debt rating was upgraded earlier this week.

Advanced Micro Devices Inc. (NYSE: AMD) is down 13.4% at $3.80. The chipmaker’s shares took a beating today after Goldman said that the stock was overpriced.

Stay tuned for Friday. Minneapolis Fed President Narayana Kocherlakota is giving a speech. We have (also) noted the following events on the schedule (all times Eastern):

• 9:55 a.m. – University of Michigan/Thomson Reuters consumer sentiment index
• 10:00 a.m. – Leading indicators

SunPower earned $0.06 a share in the first quarter on revenues of $635 million. For the second quarter ending in June, the company now forecasts adjusted EPS between $0.05 and $0.15 on revenues of $550 million to $600 million. The consensus estimates had called for a net loss of $0.02 per share on revenues of $513.31 million.

For the full-year, SunPower now estimates adjusted EPS in the range of $0.60 to $0.80 on revenues of $2.5 to $2.6 billion. These estimates are pretty much inline with the current consensus for EPS of $0.64 on revenues of $2.55 billion.

The company said it would provide detail on its guidance in a conference call later this morning. But the construction of its Antelope Valley Ranch project and its success at lease financing are likely to be the reasons for the company’s optimism for the current year.

Investors like what they have read so far. Shares are about 7.3% in premarket trading this morning, at $20.41, which would be a new 52-week high if it holds. The current 52-week range is $3.71 to $19.50.

Tesla’s CEO, Elon Musk, is also the chairman of SolarCity Corp. (NASDAQ: SCTY), which last night reported earnings for the second time since going public late last year. Like Tesla, since the beginning of this year the stock chart has that fabulous “hockey-stick” outline. SolarCity’s shares also rose more than 60% since Tesla announced earnings last week, and posted a post-IPO high of $39.00 just yesterday. SolarCity’s market value is around $2.6 billion and shares trade at a forward multiple that approaches infinity because the company hasn’t yet posted a profit.

SolarCity is expected to continue posting net losses through 2014. As we noted in our coverage of the company’s earnings last night, that will likely keep short interest in SolarCity’s stock fairly high. It’s around 15% as of April 30th.

One effort that may bring a substantial benefit to SolarCity is legislation currently being discussed in a Congressional committee that would allow renewable energy companies to operate as master limited partnerships (MLPs). The legislation removes the restriction currently written into the law that limits MLPs to depletable resources.

SolarCity has received private funding to purchase and install solar PV systems at no cost to the home or business owner. The company makes money by signing a long-term power purchase agreement with the owner. Being able to raise capital on the basis of future guaranteed revenue, in much the same way that a pipeline MLP now operates, could make a vital difference to the survival of SolarCity and other companies with installation operations, including First Solar Inc. (NASDAQ: FSLR), SunPower Corp. (NASDAQ: SPWR), and MEMC Electronic Materials Inc. (NYSE: WFR).

If MLPs are eventually allowed for renewable energy projects, an estimated $6 billion in new capital could become available for companies like SolarCity. That might make a big difference in the length of time it takes for the company to become profitable.

For China-based firms, the percentage of shares short is not available because the companies are also listed on other exchanges.

Canadian Solar Inc. (NASDAQ: CSIQ) saw short interest rise by 8.3% to 2.08 million shares, about 6.8% of the company’s total float.

First Solar Inc. (NASDAQ: FSLR) short interest drop by 7.4% to 17.07 million shares, which represents 28.1% of the company’s float.

GT Advanced Technologies Inc. (NASDAQ: GTAT) showed an increase of 8% in short interest to 41.34 million shares, about 34.9% of GT’s float.

MEMC Electronic Materials Inc. (NYSE: WFR) showed an increase of 8% in short interest to 16.88 million shares, or about 7.3% of MEMC’s float.

SunPower Corp. (NASDAQ: SPWR) saw short interest rise by 4.1% to 9.52 million shares, or 23.9% of the company’s total float.

JA Solar Holdings Co. Ltd. (NASDAQ: JASO) showed a drop of 17% in short interest to 2.21 million shares.

LDK Solar Co. Inc. (NYSE: LDK) saw short interest fall by 11.9% to 3.03 million shares.

Suntech Power Holdings Co. Ltd. (NYSE: STP) showed a rise of 11.2% in short interest to 18.46 million shares.

Trina Solar Ltd. (NYSE: TSL) saw a short interest decline of 2.3% to 15.79 million shares.

Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) showed a drop of 0.3% in short interest to 7.51 million shares.

In the prior two-week period, Yingli’s short interest rose by 50%. In the most recent two weeks, the very modest rise appears to have drawn a line on just how bad investors think the company’s prospects are. The decline in short interest in LDK is likely due to a lack of fallout from its missed debt repayment. The company may be able to hold on, but that is still questionable. So far the government has not ridden to the rescue for either company, but the thinking may be that it is about to do so.

When First Solar Inc. (NASDAQ: FSLR) reported first-quarter 2013 results after the markets closed last night, investors did not know whether to cheer or boo. Share prices rose and fell and rose again in after-hours trading. But the verdict appears to be in this morning, as the stock is down about 9% after posting a new 52-week high yesterday.

Shares of First Solar jumped 27% in one day early last month following the company’s upward revision of it fiscal year 2013 guidance. The company guided revenues and EPS well higher, and last night reaffirmed that guidance. But the damage had been done.

SunPower Corp. (NASDAQ: SPWR), lately the darling of the solar sector, is down more than 5% today. The Chinese solar makers are faring worse perhaps. LDK Solar Co. Ltd. (NYSE: LDK) is down nearly 6%, JinkoSolar Holding Co. Ltd. (NYSE: JKS) is down more than 6% and Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) is down more than 3%.

First Solar’s CEO tried to put a positive spin on first quarter results by focusing on the company’s project pipeline. But when asked how much of that pipeline could be expected to be converted into booked orders, he said, “It’s future opportunities, it’s not really capable of that kind of analysis.”

Investors have made up their own minds about those “future opportunities,” not just at First Solar but at the other solar makers as well: those opportunities are at least partially wishful thinking. How big a part remains to be seen, but it seems pretty clear that SunPower’s results, posted last week, are destined to be the top of the market for solar stocks for at least another quarter or two.

The U.S. dollar index is trading down 0.14% today, now at 82.105. The GSCI commodity index is up 1.9% at 622.62. WTI crude oil closed up 1.7%, at $95.61 a barrel to close the week with a gain of 2.8%. Brent crude trades up 1.4% at $104.29 a barrel. Natural gas is up 0.6% today at about $4.05 per million BTUs. Gold settled down 0.2% today at $1,464.20 an ounce and closed the week up 0.7%.

The unofficial closing bells put the DJIA up more than 141 points to 14,972.81 (0.95%), the NASDAQ rose about 38 points (1.14%) to 3,378.63, and the S&P 500 rose 1.05% or nearly 17 points to 1,614.34.

There were a several analyst upgrades and downgrades today, including:

• Allstate Inc. (NYSE: ALL) raised to “Conviction Buy” list at Goldman Sachs;
• Western Refining Inc. (NYSE: WNR) raised to ‘outperform’ at Credit Suisse;
• AngloGold Ashanti Ltd. (NYSE: AU) cut to ‘sell’ at Goldman Sachs;
• Sysco Corp. (NYSE: SYY) cut to ‘sell’ at Cantor Fitzgerald; and
• MBIA Inc. (NYSE: MBI) cut to ‘strong sell’ at S&P Capital IQ.

Earnings reports since markets closed last night resulted in some price moves today, including these as of the last half hour of trading:

• American International Group Inc. (NYSE: AIG) is up 6.1% at $44.69 after posting a new 52-week high of $44.90 earlier today;
• Gilead Sciences Inc. (NASDAQ: GILD) is up 5.8% at $55.18 after posting a new 52-week high of $56.35 earlier today;
• Kraft Foods Group Inc. (NASDAQ: KRFT) is up 5.1% at $53.11 after posting a new 52-week high of $54.10 earlier today;
• LinkedIn Corp. (NYSE: LNKD) is down 13.3% at $174.82 (more coverage here);
• SunPower Corp. (NASDAQ: SPWR) is down 2.4% at $14.93 (more coverage here);
• Automatic Data Processing Inc. (NYSE: ADT) is up 2.7% at $69.21, a new 52-week high; and
• Duke Energy Corp. (NYSE: DUK) is down 0.5% at $74.41.

Before markets open Monday morning we are scheduled to hear earnings reports from Apollo Global Management LLC (NYSE: APO), Bridgepoint Education Inc. (NYSE: BPE), Sysco Corp. (NYSE: SYY), and Westlake Chemical Corp. (NYSE: WLK).

Some standouts among heavily traded stocks today include:

Arena Pharmaceuticals (NASDAQ: ARNA) is down 9% at $7.64. The drug maker has withdrawn its application for approval of a weight-loss drug in Europe. More coverage here.

American Capital Agency Corp. (NASDAQ: AGNC) is down 8.1% at $30.42. The mortgage REIT reported terrible results after markets closed last night.

Weatherford International Inc. (NYSE: WFT) is up 8.3% at $13.74. The oil field services company expects a profit boost from its Mexican operations.

Stay tuned for Monday. We have noted the following events on the schedule (all times Eastern):

• 11:30 a.m. – 3- and 6-month bill auctions
• 3:00 p.m. – Treasury STRIPS

Have a great weekend!

SunPower issued earnings of $0.22 per share versus a $0.10 estimate and sales were down almost 1% to $575 million. That drop may sound bad, but the expectations were only about $510 million. What is also interesting here at a time that solar companies are having a hard time is that GAAP gross margin was 9.3% versus 9.2% a year ago, and non-GAAP gross margin was 22.7% versus 12.7% a year ago.

The company claims that its results are from its superior solar panel technology combined with strong performance from rooftop and ground mount solar operations. SunPower also said that it has started initial construction of the 579-megawatt Antelope Valley Solar Projects for MidAmerican Solar and reached 90% completion on the California Valley Solar Ranch project owned by NRG Energy.

What will be a driving force here for the solar sector is that SunPower also claims that demand in the residential lease business remains solid and has again exceeded its expectations. SunPower shares gained a whopping 17% to $15.29 today. The stock hit a new 52-week high and its new 52-week range is $3.71 to $15.46.

First Solar Inc. (NASDAQ: FSLR) rose late in the day, but it closed up only 1.35% at $46.40. if you will recall, First Solar blew away its earnings guidance as well.

SolarCity Corp. (NASDAQ: SCTY) should have done well based upon the commentary, but a Goldman Sachs downgrade from this morning kept pressure there for it to close down 3.25% at $27.09. Equipment maker GT Advanced Technologies Inc. (NASDAQ: GTAT) was also lower on the day after cutting its at-risk order backlog from expectations. Shares did close down almost 5% at $3.67 today, but its shares were down around $3.54 before the SunPower news came out.

A late day pop was seen in the Guggenheim Solar (NYSEMKT: TAN) ETF and it closed up 2.2% at $20.39 on the day. Even the more diverse PowerShares WilderHill Clean Energy (NYSEMKT: PBW) ETF saw a late day surge and it closed up 2.5% at $4.80.

The U.S. dollar index is trading up 0.91% today, now at 82.226. The GSCI commodity index is down 2.1% at 611.06. WTI crude oil closed up 3.2%, at $93.99 a barrel. Brent crude trades up 2.9% at $102.83 a barrel. Natural gas is down 6.4% today at about $4.05 per million BTUs on a larger-than-expected build in U.S. inventories (more coverage here). Gold settled up 1.5% today at $1,467.60 an ounce.

The unofficial closing bells put the DJIA up more than 131 points to 14,831.58 (0.89%), the NASDAQ rose about 41 points (1.26%) to 3,340.62, and the S&P 500 rose 0.94% or nearly 15 points to 1,597.59.

There were a several analyst upgrades and downgrades today, including Yelp Inc. (NYSE: YELP) raised to ‘market perform’ at Northland Securities; Invesco Ltd. (NYSE: IVZ) raised to ‘buy’ at Sterne Agee; Arch Coal Inc. (NYSE: ACI) raised to ‘equal weight’ at Morgan Stanley; Genco Shipping & Trading Ltd. (NYSE: GNK) cut to ‘underperform’ at Credit Suisse; and SolarCity Corp. (NASDAQ: SCTY) cut to ‘neutral’ at Goldman Sachs.

Earnings reports since markets closed last night resulted in some price moves today, including these as of the last half hour of trading: Archer Daniels Midland Co. (NYSE: ADM) is down fractionally at $33.58; Avis Budget Group Inc. (NASDAQ: CAR) is up 1.4% at $28.85; CBS Corp. (NYSE: CBS) is up 2.6% at $47.62 after posting a new 52-week high of $48.30 earlier today; Facebook Inc. (NASDAQ: FB) is up 5.6% at $28.97 (more coverage here); JDS Uniphase Corp. (NASDAQ: JDSU) is up 4% at $13.02; Las Vegas Sands Corp. (NYSE: LVS) is up 1.5% at $57.09 after posting a new 52-week high of $57.88 earlier today (more coverage here); Seagate Technology PLC (NASDAQ: STX) is up 7.5% at $39.71 after posting a new 52-week high of $39.92 earlier today; Tesoro Corp. (NYSE: TSO) is up 5.8% at $53.83; Visa Inc. (NYSE: V) is up 5.7% at $175.44 after posting a new 52-week high of $179.66 earlier today; Alpha Natural Resources Inc. (NYSE: ANR) is down 4.2% at $7.16 (more coverage here); Cigna Corp. (NYSE: CI) is up 4.2% at $68.10 after posting a new 52-week high of $68.87 earlier today; Goldcorp Inc. (NYSE: GG) is down 0.6% at $28.67(more coverage here); and Monster Worldwide Inc. (NYSE: MWW) is up 8.3% at $4.64.

Before markets open tomorrow morning we are scheduled to hear earnings reports from American International Group Inc. (NYSE: AIG), Gilead Sciences Inc. (NASDAQ: GILD), Kraft Foods Group Inc. (NASDAQ: KRFT), LinkedIn Corp. (NYSE: LNKD), SunPower Corp. (NASDAQ: SPWR), Automatic Data Processing Inc. (NYSE: ADT), and Duke Energy Corp. (NYSE: DUK).

Some standouts among heavily traded stocks today include:

MGM Resorts International (NYSE: MGM) is up 6.7% at $14.73 after posting a new 52-week high of $14.90 earlier today. The hotel and casino operator posted a surprise profit on the strength of its Macau business.

Halcon Resources Corp. (NYSE: HK) is down 9% at $5.72. The independent energy company reported poor earnings this morning.

ING U.S. Inc. (NYSE: VOYA) is up 5.7% at $20.62. The U.S. insurance arm of Dutch giant ING held its IPO today. More coverage here.

Stay tuned for Friday. Fed Governor Daniel Tarullo and Richmond Fed President Jeffrey Lacker are giving speeches. We have also noted the following events on the schedule (all times Eastern):

• 8:30 a.m. – Non-farm payrolls and employment situation
• 10:00 a.m. – Factory orders
• 10:00 a.m. – ISM non-manufacturing index