The market was down 6.6% yesterday, the biggest one-day loss since 2008, and 13.5% over the past week. Intelligent investors must question whether the world is actually 10% worse the past week or if this is just fear run amok. In my opinion, it is the latter; the fear was best exemplified by a great CNN headline: "Sell First, Ask Questions Later." In any case, financials led the way yesterday with a 10% loss, followed by the energy sector with an 8.3% loss. After surveying the wreckage, there are some compelling buys out there. Read along, and I'll reveal seven stocks you can buy now.

Shipping:
DryShips (Nasdaq: DRYS) -- If you are unfamiliar, DryShips had historically run dry bulk ships, and it currently has the largest fleet of any publicly traded dry bulk shipper. However, in 2007, it added more debt to its balance sheet and acquired a Norwegian oil drilling rig business called Ocean Rig. It then spent a fortune expanding its drilling rig fleet. This decision is paying off now. The dry shipping business is down in the dumps, but the oil rig business is doing well. This combination of bad business, good business, and debt has some Fools calling Dryships the greatest gamble in stocks. It gets spicier. First, two weeks ago, DryShips announced plans to acquire OceanFreight, a dry bulk shipper with four Capesizes, two Panamaxes, and contracts to acquire five very large ore carriers, or VLOCs.

Second, DryShips plans on spinning off its Ocean Rig business in the next year or so. The company sold a 22% stake to investors in December for $500 million, valuing the oil rig business at just under $2.3 billion. Last week, the company announced it would do a partial spinoff of 2% of Ocean Rig in September, followed by a full spinoff at some point in the future.

The stock is down nearly 40% in the past month. At this level, while the risks are high -- the company has a huge $2.9 billion debt load -- the potential rewards are high enough to warrant a speculative position. This company could go to zero or be a 10-bagger. I wouldn't risk any money I wasn't willing to lose, but it is surely worth a small position.

Teekay LNG Partners LP (NYSE: TGP) -- Teekay LNG provides marine transportation for liquefied natural gas, or LNG, and crude oil under long-term contracts. The global trade in oil is huge, and the market for LNG is greatly expanding. Over the past five years, Teekay LNG Partners has grown from four LNG carriers and five tankers to 21 LNG carriers, five LPG carriers, and 11 conventional oil tankers. The company is organized as an MLP and has increased its distributions at an 8% five-year CAGR to $2.52 per share last year, for nearly an 8.5% yield. The company is well-positioned to grow with the LNG market, wherever that may be.

Natural gas:
Chesapeake Energy (NYSE: CHK) and Ultra Petroleum (NYSE: UPL) are the two stocks I like most in natural gas.

Ultra Petroleum has some of the lowest costs in the industry and a very strong management team. As other companies struggle with $4/mcf natural gas prices, Ultra's $2.68/mcf cost allows it to profit while others have to adapt. Over the last five years, Ultra has increased its proved reserves at 17% annualized, and its production at 24% annualized. In the past week, Ultra has fallen just more than 10%, so I think it's a good time to add shares.

Unlike Ultra, Chesapeake Energy has had to adapt. The company has large acreage positions in almost every big field in the U.S., which should support future production growth for quite some time. The company has been shifting its production focus from natural gas to natural gas liquids and oil. Under investor criticism, the company announced a strategy to raise its share price by increasing production to increase cash flow and selling assets to reduce debt. While Chesapeake doesn't have the lowest costs, for the price shares are trading at, the stock provides a good risk/reward ratio.

Oil:
SandRidge (NYSE: SD) was started by Tom Ward, who co-founded Chesapeake Energy with Aubrey McClendon. SandRidge realized in 2009 that there was going to be a glut of natural gas in the U.S., so Tom Ward decided to purchase Arena Resources to switch SandRidge's production focus to oil. The company drills shallow wells in the Permian Basin of West Texas and the Mississippian play in Oklahoma and Kansas, which are able to be completed quickly and at a low cost. As fellow Fool Paul Chi detailed yesterday, there's a lot to like about SandRidge, especially its price, which is 35% lower than a week ago. Click here for a detailed write-up.

Infrastructure:
Tenaris (NYSE: TS) is a global producer of oil country tubular goods, or OCTG, products based in Luxembourg. Think drilling pipes and pipelines. I've written before on the huge opportunity the next 25 years will be for pipe manufacturers. Tenaris is well-positioned to capitalize on the pipeline boom, since tubular products make up 87% of its business.

When I wrote about it before, I noted that Tenaris was not particularly cheap, trading at roughly 22 times earnings. In the past month, the stock has fallen over 25%, and its $1.2 billion in earnings now leave the stock with a much more reasonable P/E of 16.5. Tenaris' direct exposure to the OCTG business should allow its investors to best cash in on the pipeline boom.

My seventh energy stock to buy now
My last energy idea is really a combination of two stocks. Last month, besides Tenaris, I highlighted a second stock to profit from the pipeline boom. One week later, news broke that the company I chose will be acquired by one of my other favorite energy companies. We've profiled that acquirer in a free report: "The Only Energy Stock You'll Ever Need." To find out the name of my seventh stock to buy now, click here to grab a copy of that report, absolutely free.