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Sumitomo copper affair

Sumitomo copper affair is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sumitomo copper affair rather than just read about it. In short: The Sumitomo copper affair refers to a metal trading scandal in 1996 involving Yasuo Hamanaka, the chief copper trader of the Japanese trading house Sumitomo Corporation (Sumitomo). The scandal involves unauthorized trading over a 10-year period by Hamanaka, which led Sumitomo to announce US$1.8 billion in related losses in 1996 when Hamanaka's trading was discovered, and more related losses subsequently.

Sumitomo copper affair — main illustration
Sumitomo copper affair — illustration

Key takeaways

  • Sumitomo copper affair belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Sumitomo copper affair to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Sumitomo copper affair from memory before moving on to harder problems.

Reference excerpt

The Sumitomo copper affair refers to a metal trading scandal in 1996 involving Yasuo Hamanaka, the chief copper trader of the Japanese trading house Sumitomo Corporation (Sumitomo). The scandal involves unauthorized trading over a 10-year period by Hamanaka, which led Sumitomo to announce US$1.8 billion in related losses in 1996 when Hamanaka's trading was discovered, and more related losses subsequently. The scandal also involved Hamanaka's attempts to corner the entire world's copper market through LME Copper futures contracts on the London Metal Exchange (LME). The affair was a major scandal which is at times compared in magnitude to the Silver Thursday scandal, involving the Hunt family's attempt to corner the world's silver markets. It currently ranks in the top 10 trading losses in financial history.

Hamanaka's decade of unauthorized trading Hamanaka and his superior, Saburo Shimizu, began speculating without authorization using copper forward contracts on the LME in 1985 in an attempt to recoup an earlier loss from their trading in physical copper in the Philippines. They were not successful, and their losses rose to US$60 million. Shimizu resigned at this point. Both traders felt that they could not report these losses to their superiors, but Hamanaka believed he could recover the losses through further trading. Hamanaka would state later at his trial in 1997 that his motivation for the scheme was to cover earlier losses, both before and during his promotion to Sumitomo's head copper trader, and not for personal gain. Shimizu supports his account of this motivation. Whatever his motivations, Hamanaka hid his losses by keeping a secret book of unauthorized trading, and by destroying documents, lying to his supervisors, forging trading data, and forging signatures. These tactics successfully hid his activities and Sumitomo promoted him to head copper trader in 1986.

Different schemes to recoup losses To recoup his earlier trading losses, Hamanaka embarked on a variety of schemes to profitably trade copper by cornering the market. Depending on the context, prosecutors usually focus on just one or two of the schemes depending on their interest and jurisdiction. Hamanaka's dealings with David Campbell began in 1989 with a discussion about his intentions of driving up the copper price by cornering the world market. Campbell was then president of the private metals trading firm RST Resources, inc. (RST). From 1989 to 1992, Hamanaka conducted significant amounts of business with RST, and became the firm's biggest client. In 1993, Campbell resigned from RST and founded Global Minerals and Mining Corp (Global), and Hamanaka switched to doing business with Global. Hamanaka entered into a string of monthly purchasing agreements with Global from 1994 to 1997. Hamanaka would purchase physical copper warrants, or claims on physical copper stored in warehouses, from Global, which purchased them from a Zambian copper producer. Hamanaka would then sell the warrants back to the Zambian producer to repeat the cycle. These transactions allowed Hamanaka to establish the appearance of a real copper business, and to allow him to claim commercial hedging justification to establish large futures positions to supposedly hedge the illusory transactions. With the false commercial justification established, Hamanaka established a massive long copper futures contract position on the LME through an account established at Merrill Lynch for Global and through other small brokers. By September 1995, Sumitomo possessed two million tonnes of copper in the form of futures contracts, and nearly one half of LME Copper warrants. At this point, Hamanaka began to take delivery of copper warrants from expiring LME Copper contracts, which consolidated his control over the copper cash market. By November 24, 1995, Hamanaka controlled 93% of LME Copper warrants, and a dominant position in the LME Copper futures contract market. This forced traders who were short LME Copper futures, and who could not deliver physical copper, to purchase LME Copper futures from Hamanaka at high prices near the expiry of the contract to offset their position. Hamanaka's dealings with David Threlkeld resulted in two attempts to warn the LME about Hamanaka's trading practices. Threlkeld's company, DLT Inc, traded copper for Hamanaka, and Paul Scully, a DLT employee, warned Threlkeld about problems in Hamanaka's trading practices in 1991. Scully would die in a July 1991 fire, which raised suspicions in 1996 after Hamanaka's fraudulent trading became public; however, two investigations ruled the fire was accidental. Threlkeld had separately received faxes from Hamanaka requesting to document $500 million of non-existent trades on DLT letterhead. Threlkeld refused, and complained to the LME. The LME discussed the letter with the Securities and Investments Board and Sumitomo management. Ultimately the LME decided it did not have jurisdiction to bring enforcement action against Hamanaka, but the LME did pressure Sumitomo to release Hamanaka's letter to the public, which did not result in any repercussions to Hamanaka at the time. Threlkeld separately confronted two of his employees in the DLT London office, Charles Vincent and Ashley Levett. Threlkeld subsequently fired Vincent, and Levett quit DLT. The two traders founded Winchester Commodities Group afterwards.

Role of US banks US banks made loans to Hamanaka, sometimes in the form of unusual loan arrangements, that allowed Hamanaka to cover his losses and prolong his trading activity. As Hamanaka accumulated trading losses, he borrowed money to extend his positions or to hide losses. More than a dozen brokers at the LME had each extended on average US$150 million as credit lines to Hamanaka by mid-1993, and he faced difficulties obtaining more credit. To continue his activities, Hamanaka started borrowing from US banks in 1994. J.P. Morgan extended about US$400 million of credit to Hamanaka, and Chase Manhattan extended US$500 million. Separately, Merrill Lynch lent Hamanaka US$500 million to purchase copper warrants, and US$100 million in Commodity Inventory Purchase Obligations. Without credit from US banks, Hamanaka might not have been able to hide his losses for as long as he did, which might have led to the discovery of his trading schemes much sooner and reduced the eventual losses to Sumitomo.

… excerpt ends here. Continue reading the full article.

Illustrations

Sumitomo copper affair: A copper nugget
A copper nugget

Worked examples

Example 1 — a first encounter with Sumitomo copper affair

Start with the simplest possible case. Write down what Sumitomo copper affair claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sumitomo copper affair before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sumitomo copper affair ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sumitomo copper affair

In research
Sumitomo copper affair appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Sumitomo copper affair in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Sumitomo copper affair is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1996 in Japan, Copper, Corporate scandals, so understanding it makes those chapters shorter.
In everyday life
Look for Sumitomo copper affair outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Sumitomo copper affair in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Sumitomo copper affair means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Sumitomo copper affair out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sumitomo copper affair in simple terms?

The Sumitomo copper affair refers to a metal trading scandal in 1996 involving Yasuo Hamanaka, the chief copper trader of the Japanese trading house Sumitomo Corporation (Sumitomo). The scandal involves unauthorized trading over a 10-year period by Hamanaka, which led Sumitomo to announce US$1.8 bi…

Why does Sumitomo copper affair matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sumitomo copper affair?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sumitomo copper affair.

Tags

  • 1996 in Japan
  • Copper
  • Corporate scandals
  • Financial scandals
  • Rogue traders
  • Scandals in Japan
  • Sumitomo Group

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