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.

Except for Canadian Solar — which, despite its name, is a Chinese firm — the majority of news from Chinese solar energy firms has been somewhere between bad and awful. Suntech Power Holdings Co. Ltd. (NYSE: STP) has filed for bankruptcy, LDK Solar Co. Ltd. (NYSE: LDK) has missed a debt repayment, and the list could go on.

Analyst upgrades, including one today from R.W. Baird, to ‘outperform’ are pushing SunPower’s shares higher. The estimated earnings per share (EPS) for the first quarter have risen by $0.15 a share, from a net loss of $0.09 to a profit of $0.06 per share. SunPower has beat EPS estimates in each of the last four quarters and posted a profit in each of the last three quarters.

SunPower, which majority owned by France’s oil supermajor Total SA (NYSE: TOT) is expected to do well in the Japanese solar energy market as the country continues to rebuild its electricity generating infrastructure following the Fukushima disaster. At least one estimate puts Japan ahead of every other country except China in new solar installations during 2013. A generous subsidy in the form of a feed-in tariff for large projects and good incentives to encourage roof-top installations.

One possible brake on SunPower’s expected growth in Japan is stiff competition from Japanese solar panel makers Kyocera Corp. (NYSE: KYO) and Sharp Corp. Japanese consumers have shown a distinct preference for Japanese-made modules and panels.

Shares of SunPower are up 9% in the mid-afternoon today, at $13.24 after posting a new 52-week high of $13.90 earlier. The 52-week low is $3.71. Just a reminder: in 2011 Total paid $23.25 a share for its 60% stake in SunPower.

In the Chinese solar sector we tracked the following short interest changes: JA Solar Holdings Co. Ltd. (NASDAQ: JASO), LDK Solar Co. Inc. (NYSE: LDK), Suntech Power Holdings Co. Ltd. (NYSE: STP), Trina Solar Ltd. (NYSE: TSL) and Yingli Green Energy Holding Co. Ltd. (NYSE: YGE). 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 drop by 4.8% to 1.92 million shares, about 6.4% of the company’s total float.

First Solar Inc. (NASDAQ: FSLR) short interest rise by 12.2% to 18.43 million shares, which represents 30.6% of the company’s float.

GT Advanced Technologies Inc. (NASDAQ: GTAT) showed a decrease of 5.6% in short interest, to 38.29 million shares, about 32.3% of GT’s float.

MEMC Electronic Materials Inc. (NYSE: WFR) showed an increase of 1.4% in short interest, to 15.62 million shares, about 6.8% of MEMC’s float.

SunPower Corp. (NASDAQ: SPWR) saw short interest jump by 33.1% to 9.15 million shares, 23% of the company’s total float.

JA Solar Holdings Co. Ltd. (NASDAQ: JASO) showed a drop of 16.3% in short interest, to 2.66 million shares.

LDK Solar Co. Inc. (NYSE: LDK) saw short interest rise by 0.8% to 3.44 million shares.

Suntech Power Holdings Co. Ltd. (NYSE: STP) showed a rise of 16.6% in short interest, to 16.6 million shares.

Trina Solar Ltd. (NYSE: TSL) saw short interest decline of 15.6% to 16.15 million shares.

Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) showed a rise of 50.9% in short interest, to 7.53 million shares.

Short interest is piling up in Yingli as the company looks like the next casualty among the Chinese solar energy players. LDK is teetering on the brink of disaster already, having missed a debt repayment last week. The big thing weighing down both these firms is that it appears that China’s central government will not rescue either of them. Both Trina Solar and JA Solar are better capitalized and could muddle through without government assistance.

The sharp increase in short interest in SunPower could rise even more during these two weeks, if the share price continues to rise. The company is tagging along on the boost in First Solar’s share price and there is no fundamental reason for SunPower stock to keep rising. The company is scheduled to report earnings on May 6.

In the Chinese solar sector we tracked the following short interest changes: JA Solar Holdings Co. Ltd. (NASDAQ: JASO), LDK Solar Co. Inc. (NYSE: LDK), Suntech Power Holdings Co. Ltd. (NYSE: STP), Trina Solar Ltd. (NYSE: TSL) and Yingli Green Energy Holding Co. Ltd. (NYSE: YGE).

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 drop by 6% to 2.02 million shares, which is about 6.6% of the company’s total float.

First Solar Inc. (NASDAQ: FSLR) short interest fell by 10.8% to 16.43 million shares, which represents 27.3% of the company’s float.

GT Advanced Technologies Inc. (NASDAQ: GTAT) showed an increase of 0.8% in short interest to 40.57 million shares, about 34.3% of GT’s float.

MEMC Electronic Materials Inc. (NYSE: WFR) showed a decline of 6.4% in short interest to 15.41 million shares, about 6.7% of MEMC’s float.

SunPower Corp. (NASDAQ: SPWR) saw short interest fall by 17.6% to 6.87 million shares, or 17.3% of the company’s total float.

JA Solar Holdings Co. Ltd. (NASDAQ: JASO) showed a drop of 6.1% in short interest to 3.18 million shares.

LDK Solar Co. Inc. (NYSE: LDK) saw short interest rise by 0.2% to 3.42 million shares.

Short interest in Suntech Power Holdings Co. Ltd. (NYSE: STP) declined 45.3% to 14.24 million shares.

Trina Solar Ltd. (NYSE: TSL) saw short interest retreat 0.7% to 19.14 million shares.

Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) showed a short interest drop of 11.9% to 4.99 million shares.

Suntech’s bankruptcy filing in the second half of March cooled the ardor of short sellers for the Chinese solar stocks. Instead of piling in, short interest either declined or rose modestly in all the Chinese stocks.

The next report on short interest should reverse what we have seen today. First Solar gave the entire sector a lift yesterday when it boosted its outlook for 2013 and share prices rose dramatically. Anyone caught short yesterday in any solar stock very likely got a bad sunburn. But nothing much has really changed in the sector: module prices are a little more stable but remain low, and government support for solar installations is not growing. Look for the shorts to wade back in.

In the past three years, some 40 China-based firms have announced deals to take the company private and nearly half the deals have been backed by private equity firms. One of the largest is the $3.7 billion deal to take private China’s premier display advertising firm, Focus Media Holding Ltd. (NASDAQ: FMCN). The Carlyle Group L.P. (NASDAQ: CG) is joining with the company’s CEO in the buyout.

Other recent take-private deals include one for Zhongpin Inc. (NASDAQ: HOGS) and another for fertilizer maker Yongye International Inc. (NASDAQ: YONG). Zhongpin’s chairman is taking the company private on his own, and Yongye’s CEO is getting help from a branch of Morgan Stanley (NYSE: MS). Carlyle Group is also involved in going-private deal worth $688 million for 7 Days Group Holdings Ltd. (NYSE: SNN). Chinese pharmaceutical maker Simcere Pharmaceutical Group (NYSE: SCR) also got an offer from its chairman to take the drug maker private.

One question follows from all this activity: what about China’s struggling solar makers? Now that Suntech Power Holdings Co. Ltd. (NYSE: STP) is no longer a factor, it is interesting to speculate on the possibility of a take-private deal for one of the other solar players. Names that spring immediately to mind are LDK Solar Co. Ltd. (NYSE: LDK), Trina Solar Ltd. (NYSE: TSL), Canadian Solar Inc. (NASDAQ: CSIQ) and ReneSola Ltd. (NYSE: SOL).

LDK has issued 12 million newly minted shares to Fulai Investments, giving the firm about 11% of the company. A state-controlled firm owns another 20% of LDK. With a current total market cap of just $141 million, LDK would seem ripe for a take-private deal, especially after shedding one of its largest plants to a provincial government. A government-engineered takeover is more likely here due to the government’s heavy involvement with LDK already.

Trina is one of the companies expected to get some benefit from the downfall of Suntech. The company says it will meet $83.5 million loan payment due July 15. There has been no indication that Trina is being targeted for a take-private deal, but with a market cap of around $260 million the opportunity is there.

Canadian Solar, with a market cap of just $150 million, could be another take-private candidate. The company has a solar installation business, and that promises to help make up for the low prices for wafers and modules. Earlier this year the company got a $40 million loan from Credit Suisse to acquire four projects in Ontario.

ReneSola just received a $51 million loan from a Chinese government-controlled bank, and with a market cap below $125 million, this one is the cheapest of the bunch. But again, the government stake in ReneSola is a negative to taking the company private.

Perhaps the biggest issue with taking a solar company — or any other for that matter — private is how good the chances are that the company can be floated to the public again. No private equity fund is going to bail in to a deal without a clear plan for bailing out. There are not likely to be a lot more buyers for solar makers in another two or three years.

For founders and company executives, taking a Chinese firm private could be a matter of pride. Because these are the very guys who drove the companies to the brink of extinction in the first place, partnering with them seems needlessly risky. Suggestions that firms might consolidate also are unlikely to get much traction in China, again mainly as a matter of pride.

As with so many things in China, the government likely will be responsible for picking winners and losers in the solar business. The government surely could have rescued Suntech, but chose not to. On that basis, the loan to ReneSola is encouraging for that firm.

From here, though, LDK continues to look like the next target, and it will not be a buyout but a government takeover in some form. Trying a merger arbitrage play here, just in case a buyer should pop up, could be a safe bet with some possible upside if the government eventually does ride to the rescue.

In the Chinese solar sector we tracked the following short interest changes: JA Solar Holdings Co. Ltd. (NASDAQ: JASO), LDK Solar Co. Inc. (NYSE: LDK), Suntech Power Holdings Co. Ltd. (NYSE: STP), Trina Solar Ltd. (NYSE: TSL) and Yingli Green Energy Holding Co. Ltd. (NYSE: YGE).

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 0.5% to 2.15 million shares. That is 7.1% of the company’s total float.

First Solar Inc. (NASDAQ: FSLR) short interest rose by 3.7% to 18.42 million shares, which represents 30.6% of the company’s float.

GT Advanced Technologies Inc. (NASDAQ: GTAT) showed an increase of 5.2% in short interest, to 40.25 million shares, or about 33.9% of GT’s float.

Short interest in MEMC Electronic Materials Inc. (NYSE: WFR) declined 1.7% to 16.46 million shares, about 7.2% of MEMC’s float.

SunPower Corp. (NASDAQ: SPWR) saw short interest fall by 16% to 8.34 million shares, or 21% of the company’s total float.

JA Solar Holdings Co. Ltd. (NASDAQ: JASO) showed an increase of 0.7% in short interest, to 3.38 million shares.

LDK Solar Co. Inc. (NYSE: LDK) saw short interest decline of 3.9% to 3.41 million shares.

Suntech Power Holdings Co. Ltd. (NYSE: STP) had a drop of 8.6% in short interest, to 26.03 million shares.

Trina Solar Ltd. (NYSE: TSL) saw short interest rise of 1.5% to 19.28 million shares.

Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) showed a drop of 0.2% in short interest, to 5.66 million shares.

The bankruptcy filing by Suntech happened after March 15, so any impact on other solar players has not shown up yet. JA Solar got a reprieve shortly after the Suntech fiasco, and it looks like both Trina and Yingli will make it through the shakeout in Chinese solar stocks. LDK Solar remains the weakest of the current survivors.

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 3.5% to 2.14 million shares, which is 7.1% of the company’s total float.

First Solar Inc. (NASDAQ: FSLR) short interest increased by 6.4% to 17.77 million shares, which represents 29.5% of the company’s float.

GT Advanced Technologies Inc. (NASDAQ: GTAT) showed an increase of 8.3% in short interest, to 38.26 million shares, or about 32.2% of GT’s float.

The short interest in MEMC Electronic Materials Inc. (NYSE: WFR) grew 2.1% to 16.74 million shares, about 7.3% of MEMC’s float.

SunPower Corp. (NASDAQ: SPWR) saw short interest rise by 11.9% to 9.93 million shares, 25% of the company’s total float.

J.A. Solar Holdings Co. Ltd. (NASDAQ: JASO) showed an increase of 15.4% in short interest to 3.36 million shares.

LDK Solar Co. Inc. (NYSE: LDK) saw short interest decline of 19% to 3.55 million shares.

Suntech Power Holdings Co. Ltd. (NYSE: STP) showed a rise of 4.2% in short interest to 28.46 million shares.

Trina Solar Ltd. (NYSE: TSL) saw short interest rise of 5.6% to 19 million shares.

Yingli Green Energy Holding Co. Ltd. (NYSE: YGE) showed a rise of 5.6% in short interest to 5.67 million shares.

Shares of the Chinese solar stocks continue to be volatile, and share prices are tied to news related to government spending on planned solar installation in China during 2013. First Solar’s weak earnings brought some shorts back. And short interest in SunPower jumped again, likely due to the belief that there is not much good news coming from the firm, which has seen share prices spike in the first few months of the year.

China Auto Logistics Inc. (NASDAQ: CALI) is up 88.8% at $5.21.

B.O.S. Better Online Solutions Ltd. (NASDAQ: BOSC) is up 44.6% at $3.85.

Elecsys Corp. (NASDAQ: ESYS) is up 32.2% at $5.30.

Parametric Sound Corp. (NASDAQ: PAMT) is up 21.3% at $17.74.

CombiMatrix Corp. (NASDAQ: CBMX) is up 18.2% at $3.76.

And here are today’s five biggest losing stocks at closing:

AEterna Zentaris Inc. (NASDAQ: AEZS) is down 22.5% at $2.03.

Canadian Solar Inc. (NASDAQ: CSIQ) is down 15.6% at $3.15.

Orient Paper Inc. (NYSEMKT: ONP) is down 12.1% at $1.96.

Nevsun Resources Ltd. (NYSEMKT: NSU) is down 11.2% at $3.49.

China Metro-Rural Holdings Ltd. (NYSEMKT: CNR) is down 9.9% at $1.00.

The U.S. dollar index fell 0.12% today, now at 82.589. The GSCI commodity index is up 0.3% at 648.81, with commodities prices mixed again today. WTI crude oil closed up 0.1% today, at $92.06 a barrel. Brent crude trades down 0.7% at $110.10 a barrel. Natural gas is up 0.4% today at about $3.65 per million BTUs. Gold settled up 0.1% today at $1,578.00 an ounce.

The unofficial closing bells put the DJIA up about 50 points to 14,447.22 (0.35%), the NASDAQ rose nearly 9 points (0.26%) to 3,252.87, and the S&P 500 rose 0.32% or about 5 points to 1,556.22.

There were a several analyst upgrades and downgrades today, including Best Buy Co. Inc. (NYSE: BBY) raised to ‘overweight’ at Piper Jaffray; Peabody Energy Corp. (NYSE: BTU) cut to ‘market perform’ at BMO; Smithfield Foods Inc. (NYSE: SFD) raised to ‘neutral’ at BofA/Merrill Lynch; Adobe Systems Inc. (NASDAQ: ADBE) cut to ‘neutral’ at BofA/Merrill Lynch; and ArcelorMittal (NYSE: MT) raised to ‘buy’ at UBS.

Earnings reports since markets closed last Friday resulted in several price moves today, including these: Canadian Solar Inc. (NASDAQ: CSIQ) is down 14.6% at $3.19 (more coverage here); Chyron Corp. (NASDAQ: CHYR) is up 8.6% at $0.93; and Renren Inc. (NASDAQ: RENN) is up 0.7% at $3.09.

Before markets open tomorrow morning we are scheduled to hear from CVR Energy Inc. (NYSE: CVI), Diamond Foods Inc. (NASDAQ: DMND), Fuel Cell Energy Inc. (NASDAQ: FCEL), Urban Outfitters Inc. (NASDAQ: URBN), Bon-Ton Stores Inc. (NASDAQ: BONT), and Stage Stores Inc. (NYSE: SSI)

Some standouts among high-volume stocks today include:

BlackBerry (NASDAQ: BBRY) is up 13.4% at $14.81. The mobile phone maker got a boost from an announcement that AT&T Inc. (NYSE: T) would begin accepting pre-orders tomorrow for the company’s first touchscreen phone. More coverage here.

Zynga Inc. (NASDAQ: ZNGA) is up 10.6% at $3.95. The game developer’s shares jumped this afternoon following an analyst’s comment that Yahoo! Inc. (NASDAQ: YHOO) may be interested in acquiring the company.

Dick’s Sporting Goods Inc. (NYSE: DKS) is down 10.9% at $45.11. The sporting goods retailer reported weak results and offered lower guidance than analysts were expecting. More coverage here.

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

• 7:30 a.m. – National Federation of Independent Business small business optimism index
• 11:30 a.m. – 4-week bill auction
• 1:00 p.m. – 3-year note auction
• 2:00 p.m. – Treasury budget

For the fourth quarter, the solar panel maker reported an adjusted diluted earnings per share (EPS) loss of $1.01. In the same period a year ago, Canadian Solar reported a net loss of $1.00 per share on revenue of $326 million. Fourth-quarter results also compare to the Thomson Reuters consensus estimates for a net loss of $0.95 per share and $318.53 million in revenue.

For the full year, the company reported an adjusted EPS loss of $3.04 on revenues of $1.3 billion. The consensus estimates called for a net loss of $2.90 per share on revenues of $1.31 million.

On a GAAP basis, Canadian Solar posted a quarterly net loss of $2.43 per share, compared with a loss of $1.01 a year ago. The company wrote down $31.24 million in bad debt during the fourth quarter and reserved about $30 million after an arbitrator ruled for competitor LDK Solar Co. Ltd. (NYSE: LDK) in a dispute between the two Chinese solar makers.

The company’s CEO said:

2012 was a difficult year for the entire solar industry. Despite the headwinds, we maintained our practice of balancing the desire to expand with the need for prudent business management and cost control. As a result, Canadian Solar has fared better than most of our competitors. We have further increased our market share, and rapidly established our total solutions business with investments in the mid- and downstream segments.

That the company increased its market share may not be particularly good news for shareholders. The company’s gross margin for 2012 fell from 9.6% a year earlier to 7%. The only good news there is that Canadian Solar did not lose money on every panel it sold. Gross margin improved a bit in the fourth quarter, from 2.2% in the third quarter to 5%.

The company’s first-quarter outlook includes shipments of 290 to 310 megawatts of solar modules with a gross margin of 8% to 10%. For the full year, the company expects to ship 1,600 to 1,800 megawatts, compared with 1,543 megawatts shipped in 2012. The consensus analysts’ estimates for 2013 are EPS of $1.15 on revenue of $1.81 billion.

Shares are down about 5.6% in premarket trading, at $3.52 in a 52-week range of $1.95 to $5.15. Thomson Reuters had a consensus analyst price target of around $5.30 before today’s results were announced.