Natural gas giant Chesapeake Energy (CHK) has been in the headlines lately, with the stock attracting attention due to a substantial asset sale earlier this week. Plus, just Friday morning, CHK scored an upgrade to buy at Canaccord Genuity. The shares have gained ground as a result, with the equity up more than 13% from last Friday's close. However, bearish bets were the options of choice on CHK this morning.

Within the first hour of Friday's session, more than 5,000 puts were exchanged on CHK's January 2012 35-strike put. The majority of these puts traded near the ask price, indicating they were most likely purchased. With CHK hovering just shy of $35 at last look, these long-term options are right at the money.

Late Monday, Amgen (AMGN) unveiled positive results for its bone drug, denosumab. A clinical study of 1,432 men with hormone refractory prostate cancer revealed that denosumab, which is also known as Xgeva, improved bone metastasis-free survival by 4.2 months. However, the overall survival rate was comparable to a placebo group.

Denosumab is already used to treat osteoporosis under the brand name Prolia, and has been approved under the brand name Xgeva for the prevention of skeletal-related events (SREs) in patients with bone metastases from solid tumors. The drug has not yet been approved for the prevention of SREs in multiple myeloma patients.

Consumer-goods behemoth Unilever (UN) was among the stocks making headway Tuesday morning. The British firm received an upgrade to overweight from underweight by brokerage firm Morgan Stanley, which stated, "We double upgrade Unilever to overweight, as we see the risk/reward profile for the shares as more attractive now than at any point in the past three years."

I am not going to agree or disagree with the decision for the upgrade right now; I want to take a look at the equity's chances to further this rally (at more than 3% as of this writing). There is evidence for both the continuation and the stall of the rally

Salesforce.com (CRM) is certainly enjoying a positive post-earnings reaction Friday. After unveiling its third-quarter results last night, the stock sailed to a new all-time high as a slew of brokerage firms rushed to raise their price targets on CRM.

Specifically, CRM swung to a third-quarter profit of $21.1 million, or 15 cents per share, while revenue increased 30% to $429.1 million. Excluding items, CRM earned 32 cents per share. By contrast, analysts were looking for a quarterly profit of just 31 cents per share on revenue of $410.5 million.

Ford (F) was more than 2% higher Thursday morning thanks to an upgrade from Barclay's Capital. The brokerage house upped the automaker to overweight from equal weight and elevated Ford's price target to $16 from $15.

Barclay's feels that investors "appear to be ignoring the fundamental increase in Ford's earnings power even in a slower growth environment." The brokerage continued to say that favorable products on top of a stripped-down cost base, even assuming no further gains in the firm's U.S. market share, could lead to U.S. SAAR growth expectations by 1.5 million. This fact leads Barclay's to maintain their Ford earnings estimates materially, with a new earnings estimate of $2.00, which remains atop the consensus estimate of $1.84.

Chesapeake Energy (CHK) Monday morning was upgraded to outperform from market perform at BMO Capital. The brokerage house cited valuation as the reason for the upgrade, stating that the shares are "attractively priced at three times next year's expected discretionary cash flow compared to a median multiple of around five times at the group's larger peers," according to MarketWatch.

BMO also feels CHK's use of joint ventures to raise cash and finance capital expenditure could lead to higher cash flow yields and returns on capital, MarketWatch reported. Along with the upgrade, the ratings house assigned a price target of $30 per share for CHK.

Technology firm SanDisk (SNDK) is enjoying a nice morning thanks to favorable coverage from brokerage firm UBS.

The brokerage house upgraded SanDisk to buy from neutral and assigned a new target price of $55 per share, an elevation from $46 per share. UBS's analyst believes that strong second-half demand will outweigh any risks the stock may hold. The analyst predicts "better than expected ASP trends" continuing in the second half, combining with tight market supply to boost the shares.

Puts are flying across the tape today on Arena Pharmaceuticals (ARNA), with volume surging to 43 times the expected level within the first hour of the session. Roughly 11,000 puts changed hands by 10:40 a.m., and most of the activity was focused on ARNA's front-month strikes.

The equity's July 3 put was most active, with more than 9,000 contracts trading. Several large blocks changed hands at the ask price, implying they were most likely purchased, and implied volatility rose 18.6 percentage points as a result of the increased activity. With more than 45,000 contracts in residence at the July 3 put, it's unclear how much of this volume will translate to new open interest tomorrow; however, buyers seem to be responsible for the bulk of the activity.

After calls from a U.S. congressman for BP (BP) executives to commit hara-kiri and following President Obama's successful pressure on the company to set up a $20 billion escrow account, cancel $7.8 billion in dividend and sell $10 billion assets, a few analysts decided it couldn't get any worse and upgraded the oil giant shares to buy.

It's been nearly two months since BP's Deepwater Horizon rig exploded in the Gulf of Mexico, causing a massive oil spill -- that's still hasn't been resolved -- and the worst environmental disaster in U.S. history. Shares of the company were nearly halved as the cleanup cost estimates have swelled.

And as the agreements with Obama lifted some of the uncertainty, triggering a relief rally, some analysts also opted to upgrade BP shares.

Wednesday morning, brokerage house UBS (UBS) upgraded fellow broker JPMorgan Chase (JPM) to buy from neutral. UBS believes that JPMorgan is currently at an attractive entry point that reflects its earnings and risk while overlooking potential offsets and better footing.

UBS added that it sees "current universal bank valuations as an opportunity to get into top quality names, and JPM is as good as it gets." UBS also believes that the regulatory reform will be less strict than initially thought. In addition, UBS feels that JPMorgan's broad business mix should help the brokerage.

While economists are still worried we may see a slump in the housing market now that the homebuyer tax credits have expired, analysts still believe Home Depot (HD) is going to thrive as consumer confidence picks up and people start tackling long-overdue home-improvement projects.

An analyst at Longbow Research upgraded Home Depot from neutral to buy today -- setting a price target for the stock at $39.

Tomorrow morning before the opening bell, office retailer Office Depot (ODP) will step into the earnings spotlight. The stock is more than 8% higher this morning thanks to investors' anticipation of solid results. This anticipation was further stocked by brokerage house Credit Suisse, which upgraded ODP to "neutral" from "underperform" this morning, citing tomorrow's earnings announcement.

In addition, Jefferies & Co. forecast an improvement in the company's fist-quarter sales. Let's take a look at the technical implications of the upgrade.

Wednesday morning, Boeing (BA) posted earnings that topped the consensus estimate, but cut future forecasts in the process. Thursday morning, Credit Suisse decided to accentuate the positive for Boeing, issuing an upgrade to outperform on the air carrier. The brokerage house had rated the aerospace firm at neutral.

Technically, the stock has pulled back a bit, rebounding off the support from its 10-week moving average in the past week. This trendline is advancing through the upper $69 region and could combine with the round-number $70 level to act as double-barreled support. A glance at the bigger picture indicates that the stock could get bogged down in the $75 to $77 region, as this area provided support for the shares in the past.

Citigroup, Inc. (C) attracted a bullish note this morning from analyst Richard Bove of Rochdale Securities. The outspoken financial analyst hiked his rating on the shares from neutral to buy, citing the banking issue's healthy liquidity position.

"This gives management the flexibility to off-load the problem operations and to support longer term growth," wrote Bove in a note to clients. "It will be a money-making machine again and the stock is long-term cheap."

Bove also raised his price target on Citi shares from $3.75 to $5, implying expected upside of 28.2% to the stock's closing price on Friday.

Earlier this morning, Credit Suisse issued an upgrade for pharmaceutical firm Merck (MRK), upping the company to outperform from neutral. The brokerage noted that MRK's long-term view is positive thanks to "new interest to come from the pipeline."

Credit Suisse also gave other reasons for the move, including synergies, stronger-than-expected earnings, and potential valuation growth. The upgrade was accompanied by a target price elevation to $47 from $35. In pre-market action, MRK was higher thanks to the news.