Here’s Why These 29 Companies Fell Off the Fortune 500

That includes U.S. oil and gas companies such as Murphy Oil and Pioneer Natural Resources, who were both forced to layoff workers amid a global oil glut. The financial woes rippled out, hitting auxiliary forces in the industry including construction company KBR. And it didn’t stop there.

Financial companies including Blackstone and Alleghany saw revenues slip for fiscal year 2015, due to their equity holdings in energy companies.

The companies that fell off the Fortune 500 also serves as a snapshot of the global economy in 2015. Low oil prices hurt many industries, but the expensive dollar cut companies with global exposure more deeply. The high U.S. corporate tax rate also drove some companies to shift their headquarters abroad while maintaining operations in the states, while low interest rates and a slow-growing economy helped fuel an mergers and acquisitions boom in 2015.

Take a look at the forces that shaped out economy last year and how it affected some of the biggest companies in America:

1. KBR
Fortune 1000 Rank: No. 501
Last Appearance: No. 424

This Houston-based construction company spun off from oil giant Halliburton nearly a decade ago, but still maintains several projects in the industry. So when energy companies cut back on construction projects as a result of the oil glut, KBR (KBR) suffered. The company slid 77 spots from the year before, after sales fell 20% in 2015.

“The significant decline in commodity prices has resulted in some of our oil and gas customers taking steps to defer, suspend or terminate capital expenditures,” KBR noted in its annual report.

2. Alleghany
Fortune 1000 Rank: No. 509
Last Appearance: No. 499

A holding company that focuses largely on insurance and real estate, Alleghany’s (Y) revenue fell 4.4%, though profits dropped far more sharply—17.5%, to $560.3 million in 2015. The financial firm’s drop in profits perhaps best encompasses the political, and economic underpinnings that shaped this list: the majority of Alleghany’s losses stem from the stock market, where equities in oil, pharmaceutical, gaming, and airline companies as well as energy, and finance bonds led to a $125.5 million write down.

3. Pioneer Natural Resources
Fortune 1000 Rank: No. 522
Last Appearance: No. 496

The Irving, Texas-based oil and gas company (PXD) took a considerable hit from the oil bust, though compared to many other energy companies, it has hung on—falling just 26 positions. Pioneer managed to offset the low price of its products by selling off assets. Profits fell from $930 million a year earlier, to a loss of $273 million. Sales however fell nearly 9%.

4. Caesars Entertainment
Fortune 1000 Rank: No. 534
Last Appearance: No. 328

The resort and casino conglomerate(CZR) based out of Las Vegas tumbled off the Fortune 500 after revenues fell sharply—46% to $4.7 billion—in 2015. Though the conglomerate managed to offset the losses on its bottom line after one of its major subsidiaries, Caesars Entertainment Operating Company, filed for bankruptcy, resulting in a $7.1 billion gain after deconsolidating the holding. The gaming giant has been on a downhill slope since the financial crisis, when it was the subject of a leveraged buyout. That saddled Caesar with $18.4 billion in debt.

5. Blackstone Group
Fortune 1000 Rank: No. 536
Last Appearance: No. 373

The asset manager shed over 160 positions after sales fell 38% in 2015. Like Alleghany, Blackstone(BX) has holdings in all parts of the markets—and can attribute a large portion of its decrease in profits to a drop in performance fees. The lower performance fees in turn can be explained by lower returns in the equity markets, bonds exposed to the energy industry, and a depreciation of some real estate holdings.

6. MRC Global
Fortune 1000 Rank: No. 541
Last Appearance: No. 448

Its products “pipe, valve and fitting products” may sound a tad dry, but the Houston-based company(MRC) has a large customer base in the energy sector. Which means that, like its fellow oil-exposed compatriot, KBR, construction contracts have fallen, dragging profits down a whopping 330% in the past year.

7. General Cable
Fortune 1000 Rank: No. 544
Last Appearance: No. 443

This Highland Heights, K.Y.-based cable manufacturer (BGC) has suffered as a result of volatile copper and aluminum prices, leading to a near $122 million loss in profits, and 25% drop in sales.

8. Calumet Specialty Products Partners
Fortune 1000 Rank: No. 571
Last Appearance: No. 457

This Indianapolis-based specialty oil refiner plummeted 114 positions on the Fortune 500, largely due to its exposure to the energy sector. Calumet’s (CLMT) sales fell 27% from the year prior as a result of falling oil prices—particularly in the specialty sector, which includes lubricating oils and white oil.

9. Wynn Resorts
Fortune 1000 Rank: No. 585
Last Appearance: No. 477

It hasn’t been an easy year for hospitality and casino conglomerate, Wynn Resorts. The company has two properties operating worldwide, and one in Macau—a special administrative region of China that has been subjected to an aggressive anti-corruption campaign from Chinese President Xi Jinping. That has dissuaded high rollers from even stepping foot in the city, let alone put down their money.

10. Agilent Technologies
Fortune 1000 Rank: No. 589
Last Appearance: No. 389
Medical tech firm Agilent Technologies (A) dropped off the Fortune 500 this year after dropping 200 spots. The HP spinoff felt the cut of an expensive dollar in relation to the rest of the market, but also expenses related to spinning off its electronics and radio focused division, Keysight Technologies.

11. Advanced Micro Devices
Fortune 1000 Rank: No. 593
Last Appearance: No. 473

The tech hardware company(AMD) fell 120 positions on the Fortune 500. “We faced a challenging business environment in 2015. The impact of global macro-economic conditions, especially the volatility in the Greater China region contributed to a decrease in demand for our products,” the company noted in its annual filing with the Securities and Exchange Commission.

12. AGL Resources
Fortune 1000 Rank: No. 600
Last Appearance: No. 465

Not even Georgia-based AGL Resources(GAS) could not escape the troubles of the global oil glut last year. The 160-year-old company shed 130 ranks in on the Fortune 500, after revenues fell sharply, sending profits down nearly 27% to $353 million.

13. Buckeye Partners
Fortune 1000 Rank: No. 662
Last Appearance: No. 350

This Houston-based pipeline owner and operator(BPL) tumbled 250 positions on the Fortune 500 as lower oil prices pressed on its top line. Profits however, rose year over year, as the company managed to cut costs associated with selling refined petroleum, since the company also dealt with weak demand.

14. Murphy Oil
Fortune 1000 Rank: No. 656
Last Appearance: No. 406

Like many of its oil and gas exposed peers, Murphy Oil (MUR) tried to offset the low price of oil by cutting costs. That materialized in the form of across the board layoffs. But that still wasn’t enough. While revenue feel by over half from a year ago, Murphy oil’s profits still slid 351%, to a loss of $2.3 billion.

“Murphy Oil’s net loss in 2015 was primarily caused by impairment expense to reduce the carrying value of certain properties in the Gulf of Mexico, Western Canada and Malaysia, lower realized sales prices for oil and natural gas, lower oil and natural gas sales volumes, and the costs of exiting deepwater rig contracts in the Gulf of Mexico,” the company reported in its annual earnings.

15. Tegna
Fortune 1000 Rank: No. 681
Last appearance: 441

The broadcast television and digital media arm of Gannett (the newspaper publisher that ranks No. 752 on the Fortune 1000) was spun off in June 2015 and named Tegna. It operates 46 TV stations in the U.S. that are affiliated with Fox, CBS, and NBC.

16. ARRIS Group
Fortune 500 Rank: Inverted
Last Appearance: No. 492

ARRIS Group, a company that manufactures broadband equipment used by Comcast, TimeWarner Cable and AT&T brought in $5.3 billion in revenue in 2014. Then in April 2015, ARRIS acquired set-top box maker, Pace, based in the United Kingdom, for $2.1 billion., as part of an inversion deal, then moved its headquarters to the U.K. while keeping operations in the U.S. The inversion allows ARRIS to pay a lower corporate tax rate to the U.S. government.

17. MeadWestvaco
Fortune 500 Rank: Merged
Last Appearance: No. 464

Based out of Richmond, Va., packaging company MeadWestvaco merged with fellow packaging and paper manufacturer, RockTenn, in 2015 to form a $15 billion giant called WestRock, which ranks at No. 251 on this year’s Fortune 500.

18. Con-way
Fortune 500 Rank: Acquired
Last Appearance: No. 464

The global transportation company with a fleet of tractors, trailers, and trucks, was acquired by XPO Logistics in October, as the latter went on a multi-year acquisition spree. The $3 billion deal gave XPO direct access to the trucking market. XPO also purchased Con-way at a time when the latter was having trouble showing growth in its earnings.

19. Omnicare
Fortune 500 Rank: Acquired
Last Appearance: No. 414

Health care mergers and acquisitions have been a hotspot over the past years, as pharmaceutical stocks began to droop. Pharmaceutical services company Omnicare was no exception. The healthcare services company was acquired by an industry giant CVS Health (CVS), No. 7 on the Fortune 500, in an August deal valued at $12.9 billion.

20. Integrys Energy Group
Fortune 500 Rank: Acquired
Last Appearance: No. 404

This electricity and natural gas company was snapped up by the Wisconsin Energy Corporation, to become the WEC Group in June. The deal was valued at $9.1 billion, and allowed Wisconsin Energy to expand its coverage area, which was probably a good idea considering how slow growing the gas and electric utility industry can be.

21. Pantry
Fortune 500 Rank: Acquired
Last Appearance: No. 402

Consumers might best know the company for operating the Kangaroo Express convenience stores around the country. This Cary, N.C.-based chain was bought out by Montreal-based Alimentation Couche-Tard, the parent company of Circle K. The deal was worth $1.7 billion when it was announced in late 2014. For Alimentation, the deal represented a chance to grow into the Southern U.S.

22. PetSmart
Fortune 500 Rank: Taken Private
Last Appearance: No. 386

This Phoenix-based pet shop was taken private in March 2015, after a group of investors led by BC Partners bought out the company for $8.7 billion. As a result, the companies CEO David Lenhart and Chairman Gregory Josefowicz were forced to step down. The company went private in part due to pressure from activist investors who were pushing the company to sell itself in order to improve performance.

23. Allergan
Fortune 500 Rank: Inverted
Last Appearance: No. 380

A pharmaceutical company that has gone by many names (and therefore many mergers and acquisitions) Allergan was once based out of the U.S., before moving headquarters to Dublin, Ireland, where corporate tax rates are much, much lower. More recently, the Botox maker was nearly acquired by Pfizer in what was called the largest deal of 2015—worth $160 billion. That deal fell to pieces when the U.S. Treasury decided to unveil new rules to curb tax inversion.

24. Family Dollar Store
Fortune 500 Rank: Acquired
Last Appearance: No. 281

In a deal valued at $8.5 billion, discount retail chain Dollar Tree acquired the Family Dollar Store, and complete the process in July. The combined company now operates over 13,000 stores in 48 states and five Canadian provinces.

“This acquisition will extend our reach to low-income customers, while strengthening and diversifying our footprint,” Dollar Tree CEO Bob Sasser said in a press release.

25. Chubb
Fortune 500 Rank: Acquired
Last Appearance: No. 215

Now the largest casualty insurer in the U.S., Chubb Corp. was acquired by Zurich-based ACE, another insurance provider, in the largest insurance M&A deal ever. ACE paid about $29.5 billion for the company in July, and ended up taking on Chubb’s name. At the time, relatively mild weather and casualties had pressured the insurance industry, driving up mergers and acquisitions in the space. The company is now based out of Zurich.

26. TRW Automotive Holdings
Fortune 500 Rank: Acquired
Last Appearance: No. 175

The automotive parts maker based in Livonia, Michigan, was acquired by German parts maker ZF Friedrichshafen in a deal valued at $12.4 billion—merging to become the world’s second largest auto parts supplier.”The combined company is a powerhouse of automotive technologies, ranging from driver assistance and occupant safety systems, to drivelines and transmissions, and braking and steering systems,” said John C. Plant, CEO of TRW in a press release.

27. Kraft Food Group
Fortune 500 Rank: Merged
Last Appearance: No. 165

No stranger to the deal game, Kraft Food Group spun off from Mondelez International in 2011 before merging last year with H.J. Heinz (owned by 3G Capital and Berkshire Hathaway) to form Kraft Heinz, which ranks No. 153 on this year’s Fortune 500. The megadeal, estimated to have been worth $49 billion, came at a time when processed food makers seemed stunted. Consumers preference was, and still is, increasingly shifting toward organic, healthy, and unprocessed foods. The combined giant is now worth about $104 billion.

28. DirectTV
Fortune 500 Rank: Acquired
Last Appearance: No. 95

Satellite TV provider DirectTV was acquired in 2015 by American telecom giant, AT&T amid last year’s M&A boom. The acquisition was billed at a whopping $49 billion—creating the country’s largest pay-TV company. For AT&T, the deal was instrumental in its growth plan. DirecTV’s infrastructure would allow AT&T to roll out new products, such as over-the-top video services and mobile device streaming.

29. Safeway
Fortune 500 Rank: Taken Private
Last Appearance: No. 84

In early 2014, private equity firm, Cerberus Capital agreed to buy second largest U.S. grocery chain, Safeway, for over $9 billion dollars—taking the store private. That deal brought together Albertsons and Safeway, for a mega chain of 2,205 grocery stores. Safeway had been trying to sell itself at the time because of increasingly tough competition from Whole Foods and superstores such as Target and Walmart, making it harder for the store to grow.

Correction: In an earlier version of this story, we incorrectly identified the number of casinos operated by Wynn Resorts in Macau. This has been fixed. Fortune apologizes for the error.

ALSO READ: These 14 Companies Are Returning to the Fortune 500

ALSO READ: Here Are the 15 Companies Making Debuts on the Fortune 500

Check out the new Fortune 500 at fortune.com/fortune500 for company profiles, financial data, stock quotes, CEO videos, interactive graphics, breaking news, and more.