Question: In which city does this group that owns the New York Mercantile Exchange have exchange facilities through online trading platforms?
Context: Pepperstone is an Australian online retail foreign exchange broker specializing in foreign exchange ("forex") trading.  The company is headquartered in Melbourne, Australia and maintains offices in Dallas and Shanghai.  It provides forex trading on 72 currency pairs, metals and commodities through various online trading platforms, such as MetaTrader 4, cTrader, and a range of mobile apps. The Dubai Mercantile Exchange (DME) is a commodity exchange based in Dubai currently listing its flagship futures contract, DME Oman Crude Oil Futures Contract (OQD).  Launched in 2007, the DME aims to become the crude oil pricing benchmark for the Asian market with its Oman Crude Oil contract, like the Intercontinental Exchange’s (ICE) North Sea Brent is to Europe and the New York Mercantile Exchange’s (NYMEX) West Texas Intermediate is to North America. The New York Mercantile Exchange (NYMEX) is a commodity futures exchange owned and operated by CME Group of Chicago.  NYMEX is located at One North End Avenue in Brookfield Place in the Battery Park City section of Manhattan, New York City.  Additional offices are located in Boston, Washington, Atlanta, San Francisco, Dubai, London, and Tokyo. The Financial District, also known as FiDi, is a neighborhood located at the southern tip of the borough of Manhattan in New York City, which comprises the offices and headquarters of many of the city's major financial institutions, including the New York Stock Exchange and the Federal Reserve Bank of New York.  Anchored on Wall Street in the Financial District, New York City has been called both the most financially powerful city and the leading financial center of the world, and the New York Stock Exchange is the world's largest stock exchange by total market capitalization.  Several other major exchanges have or had headquarters in the Financial District, including the New York Mercantile Exchange, NASDAQ, the New York Board of Trade, and the former American Stock Exchange. GAIN Capital is a US-based provider of online trading services, headquartered in Bedminster, New Jersey.  The company provides market access and trade execution services in foreign exchange, contracts for difference (CFDs) and exchange-based products to retail investors.  Trading is provided via one of two electronic trading platforms, its own proprietary FOREXTrader PRO, or MetaTrader 4.  GAIN Capital allows retail and institutional clients to speculate on global foreign exchange markets in what is known as ‘margin forex trading’. The New York Cotton Exchange (NYCE) is a commodities exchange founded in 1870 by a group of one hundred cotton brokers and merchants at 1 Hanover Square in New York City.  In 1998, the New York Board of Trade (NYBOT) became the parent company of both the New York Cotton Exchange, and it is now owned by IntercontinentalExchange (ICE).  Since 2003, its headquarters and trading facility have been in the New York Mercantile Exchange Building. Investing online, also known as online trading or trading online, is a process by which individual investors and traders buy and sell securities over an electronic network, typically with a brokerage firm.  This type of trading and investing has become the norm for individual investors and traders since late 1990s with many brokers offering services via a wide variety of online trading platforms. CME Group Inc. (Chicago Mercantile Exchange & Chicago Board of Trade) is an American financial market company operating the world's largest options and futures exchange.  It owns and operates large derivatives and futures exchanges in Chicago, New York City, and exchange facilities in London, using online trading platforms.  It also owns the Dow Jones stock and financial indexes, and CME Clearing Services, which provides settlement and clearing of exchange trades.  The exchange-traded derivative contracts include futures and options based on interest rates, equity indexes, foreign exchange, energy, agricultural commodities, rare and precious metals, weather, and real estate.  It has been described by "The Economist" as "The biggest financial exchange you have never heard of." From the mid-1980s to September 2003, the inflation adjusted price of a barrel of crude oil on NYMEX was generally under $25/barrel.  Then, during 2004, the price rose above $40, and then $50.  A series of events led the price to exceed $60 by August 11, 2005, leading to a record-speed hike that reached $75 by the middle of 2006.  Prices then dropped back to $60/barrel by the early part of 2007 before rising steeply again to $92/barrel by October 2007, and $99.29/barrel for December futures in New York on November 21, 2007.  Throughout the first half of 2008, oil regularly reached record high prices.  Prices on June 27, 2008, touched $141.71/barrel, for August delivery in the New York Mercantile Exchange, amid Libya's threat to cut output, and OPEC's president predicted prices may reach $170 by the Northern summer.  The highest recorded price per barrel maximum of $147.02 was reached on July 11, 2008.  After falling below $100 in the late summer of 2008, prices rose again in late September.  On September 22, oil rose over $25 to $130 before settling again to $120.92, marking a record one-day gain of $16.37.  Electronic crude oil trading was temporarily halted by NYMEX when the daily price rise limit of $10 was reached, but the limit was reset seconds later and trading resumed. The Chicago Mercantile Exchange (CME) (often called "the Chicago Merc", or "the Merc") is an American financial and commodity derivative exchange based in Chicago and located at 20 S. Wacker Drive.  The CME was founded in 1898 as the Chicago Butter and Egg Board, an agricultural commodities exchange.  Originally, the exchange was a non-profit organization.  The Merc demutualized in November 2000, went public in December 2002, and merged with the Chicago Board of Trade in July 2007 to become a designated contract market of the CME Group Inc., which operates both markets.  The Chairman and Chief Executive Officer of CME Group is Terrence A. Duffy, Bryan Durkin is President and Leo Melamed is Chairman Emeritus.  On August 18, 2008, shareholders approved a merger with the New York Mercantile Exchange (NYMEX) and COMEX.  The Merc, CBOT, NYMEX and COMEX are now markets owned by the CME Group.
Answer: London