But selling all that stuff doesn’t necessarily mean that a company earns a profit. In fact, more than 10% of the Fortune 500 lost money in 2015, with 20 of those companies losing more than $1 billion last year, and four losing more than $10 billion. As you’ll see, many of these companies are clustered in the oil and gas sector, where the continued decline in the price of oil last year put pressure on those firms that make their profits selling petroleum and other energy-producing commodities.

But it wasn’t just the energy exploration sector that struggled in 2015, as several retailers, manufacturers and services companies made the list of 2015’s biggest billion-dollar losers. Check out the list below, after the graphic.

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The Oil Exploration Industry

There were eleven different oil and gas exploration firms on this year's Fortune 500 list that lost more than one billion dollars, including Apache (APA), Chesapeake Energy (CHK), Devon Energy (DVN), Occidental Petroleum (OXY) , Anadarko Petroleum (APC), NRG Energy (NRG), EOG Resources (EOG), ConocoPhillips (COP) , Hess (HES), Marathon Oil (MRO), and Peabody Energy (BTU).

The big losses suffered by these companies is almost entirely the result of the continued struggles of the oil and gas markets in 2015, when prices for those and other commodities plunged. Apache alone lost $23.1 billion; Chesapeake and Devon took the #2 and #3 spots will losses of $14.7 billion and $14.5 billion, respectively. Things may be looking up for many of these firms for 2016, however, as the price of oil has rebounded roughly 60% since January.

Freeport-McMoRan Inc.

Fortune 500 rank: 175
2015 loss: $12.2 billion

Freeport-McMoRan (FCX), the nation's leading metals miner, made an ill-fated bet on oil and natural gas with its $9 billion acquisition of Plains Exploration & Production Co. in 2013. The move subjected the firm to one of the worst collapses in the oil and natural gas market in history, and helped create the conditions for a year in which the firm racked up an eleven-digit loss on its earnings statement.

General Electric Co.

Fortune 500 rank: 11
2015 loss: $6.1 billion

General Electric (GE) lost $6.1 billion according to GAAP measures in 2015, but investors haven't seemed to mind, as they have bid the stock up 10% over the past year. That's because the massive loss was largely the result of a huge restructuring effort the industrial giant has taken on, which includes selling off assets like GE Capital and the company's appliance business. It's all part of an effort to refocus GE as a digital-industrial company that makes complex manufacturing equipment as well as the software to run and monitor them.

Energy Future Holdings Corp.

Fortune 500 rank: 475
2015 loss: $5.3 billion

Texas-based Energy Future Holdings had a terrible year in 2015 by any measure, except when compared to its own 2014 performance. The utility company, which was created after a 2007 leveraged buyout by KKR, TPG, and Goldman Sachs, lost $6.4 billion in 2014, meaning this year's loss counts as an improvement. The company is still struggling under the tens of billions in debt that investors foisted on the company to pay for the buyout, and is continuing to muddle through bankruptcy proceedings that began in 2014.

Baker Hughes Inc.

Fortune 500 rank: 178
2015 loss: $2.0 billion

The collapse in oil prices has affected not just oil explorers themselves, but also oilfield services companies, like Baker Hughes (BHI). The 46% decline in global rig count from the fourth quarter of 2014 through 2015 helped cause the Houston-based company's revenue to fall 36% in 2015, while the company reported a loss of roughly $2 billion.

United States Steel Corp.

Fortune 500 rank: 244
2015 loss: $2.0 billion

Steel producers faced a perfect storm of bad news in 2015, and U.S. Steel (X) was no exception. The sputtering of the Chinese economy, which consumed close to half of global steel production in 2015, hit the industry hard. That slowdown also helped create conditions for overcapacity as China's government-supported steel producers refrained from rolling back production even as demand cratered. U.S. Steel faced the added burden of a strong dollar in 2015, which made it even more difficult to compete with foreign rivals.

First Data Corporation

Fortune 500 rank: 249
2015 loss: $1.5 billion

Payments processor First Data (FDC) has spent a long time in the financial wilderness. A 2007 buyout by KKR saddled it with huge debts, just before the financial crisis helped to slash revenues and left the firm unable to compete with smaller, nimbler rivals. Before launching an IPO in October, the company made progress restructuring its debt levels and reducing interest payments, but the effects of that debt load still hampered the company, helping it lose more than $1 billion in 2015.

Icahn Enterprises L.P.

Fortune 500 rank: 184
2015 loss: $1.2 billion

Value investor Carl Icahn's publicly traded vehicle Icahn Enterprises had a rough 2015, due in large part to his sizable investments in energy-related companies like Chesapeake Energy, Freeport-McMoran, and Transocean. Other Icahn (IEP) investments like Apple also floundered in 2015, though the billionaire has since sold his shares in the tech giant.

Avon Products, Inc.

Fortune 500 rank: 370
2015 loss: $1.1 billion

Another year of big losses forced Avon (AVP) CEO to engineer a sale of its North American businesses to private equity firm Cerberus Capital Management, so that the firm could focus on its efforts in emerging markets like China and Brazil. But economic slowdowns and higher taxes in  those countries have also conspired—along with a more expensive dollar—to drag down Avon's earnings and earn them a spot on this year's list of billion-dollar losers.

Sears Holdings Corporation

Fortune 500 rank: 111
2015 loss: $1.1 billion

Everything at Sears (SHLD) seems to be shrinking, from its revenue, to same-store sales, to the number and magnitude of discounts it offers customers. Luckily for CEO Edward Lambert, the retailer's full-year losses have shrunk from 2014 too, from $1.7 billion in 2014 to $1.1 billion in 2015. Still, there is little evidence that Sears has figured out how to be profitable in an era when customers are eschewing department stores for online shopping.