Bán khống

Bách khoa toàn thư mở Wikipedia

Bán khống, trong tài chính có nghĩa là một cách kiếm lợi nhuận từ sự tụt giảm giá của một loại chứng khoán như cổ phần hay trái phiếu. Phần lớn các nhà đầu tư theo lâu dài một khoản đầu tư, hy vọng rằng giá của loại chứng khoán đó sẽ lên. Để thu lợi từ việc giá cổ phiếu đi xuống, người bán khống có thể mượn một chứng khoán và bán nó đi, mong muốn rằng nó sẽ giảm giá để người bán khống có thể mua nó lại với mức giá thấp hơn và hưởng chênh lệch giá. Thí dụ, giả sử các cổ phiếu của công ty XYZ nào đấy hiện bán với giá 10 USD một cổ phần. Một người bán khống sẽ mua 100 cổ phiếu và trả tổng cộng 1000 USD. Nếu giá cổ phiếu XYZ đó sau đó rớt xuống 8 USD một cổ phần, người bán khống đó sẽ mua lại 100 cổ phiếu đó với giá 800, trả các cổ phiếu cho người chủ gốc và được lợi nhuận 200 USD. Các làm này có nguy cơ bị lỗ vô hạn. Ví dụ, nếu cổ phiếu của XYZ được mượn được bán và trên thực tế giá lên 25 USD, thì người bán khống sẽ phải mua lại với tổng giá là 2500 USD, lỗ mất 1500 USD.



However, the term "short selling" or "being short" is often used as a blanket term for all those strategies which allow an investor to gain from the decline in price of a security. Those strategies include buying options known as puts. In fact, what is many times labeled short selling is options or futures activity, since this activity greatly magnifies the gain that results from a securities price loss. For example, if the next earnings release of XYZ company is going to show that its profits declined somewhat in some of its divisions, its stock might decline only 5 percent when that information is released. Người nào thuộc tay trong của công ty muốn mua bán thông tin nội bộ tuy nhiên có thể không được thỏa mãn với chỉ 5% lợi nhuận thu được do bán khống on his short sell and instead would buy put options or other derivatives or futures to gain possibly 20 or more percent on the decline in the stock price of XYZ.

Mục lục

[sửa] Lịch sử

Short selling has been a target of ire since at least the 18th century when England banned it outright. It was also considered a disreputable business practice because of the perceived magnifying effect it had on the violent downturn in the Dutch tulip market in the 17th century. Short sellers are widely regarded with suspicion because, to many people, they are profiting from the misfortune of others. However, academic studies have generally lauded short-selling as an important contribution to stock market efficiency.[1]

Moreover, less than 5% of all shorts are done by public investors and traders, whereas at least 95% of short sales are done by broker-dealers and market makers who do not even always have to own shares to sell them (this is called naked short selling).[cần chú thích]

The term "short" was in use from at least the mid-19th century. It is commonly understood that "short" is used because the short seller is in a deficit position with his brokerage house.

Short sellers were blamed (probably erroneously) for the Wall Street Crash of 1929. Regulations governing short selling were implemented in 1929 and in 1940. Political fallout from the 1929 crash led Congress to enact a law banning short sellers from selling shares during a sharp downturn. President Hoover condemned short sellers and even J. Edgar Hoover said he would investigate short sellers for their role in prolonging the Depression. Legislation introduced in 1940 banned mutual funds from short selling (this law was lifted in 1997).

Some typical examples of mass short-selling activity are during "bubbles", such as the Internet bubble. At such periods, short-sellers sell hoping for a market correction. Food and Drug Administration (FDA) announcements approving a drug often cause the market to react illogically due to media attention; short sellers use the opportunity to sell into the buying frenzy and wait for the exaggerated reaction to subside before covering their position. Negative news, such as litigation against a company will also entice professional traders to sell the stock short.

[sửa] Cơ chế

Việc mua-bán khống cổ phiếu bao gồm:

  • Một nhà đầu tư vay cổ phiếu, nhưng vì có một luật lệ chung ơt Hoa Kỳ quy định rằng người ta chỉ có thể vay tiền căn cứ trên các cổ phiếu lên đến 50% giá trị cổ phiếu, người vay đó phải ký quỹ 50% giá trị của cổ phiếu bằng tiền mặt với hãng môi giới của mình.
  • Nhà đầu tư bán các cổ phiếu đó và quá trình này được vào sổ tại tài khoản của hãng môi giới.
  • The investor must "close" the position by buying back the shares (called covering) - Nếu giá rớt, anh ta lời. Nếu ngược lại thì anh ta lỗ.
  • Nhà đầu tư cuối cùng trả cổ phiếu lại cho người cho vay.

[sửa] Concept

Short selling is the opposite of "going long". The short seller takes a fundamentally negative, or "bearish" stance, anticipating that the price of the shorted stock will fall (not rise as in long buying), and it will be possible to buy at a lower price whatever was sold, thereby making a profit ("selling high and buying low," to reverse the adage). The act of buying back the shares which were sold short is called 'covering the short'. Day traders and hedge funds will often use short selling to allow them to profit on trading in stocks which they believe are overvalued, just as traditional long investors attempt to profit on stocks which are undervalued by buying those stocks.

The short seller owes his broker and must repay the shortage when he covers his position. Technically, the broker usually in turn has borrowed the shares from some other investor who is holding his shares long; the broker itself seldom actually purchases the shares to loan to the short seller. [2]

Example: Borrowing 100 shares from someone, selling them immediately at $1.00 - when the stock drops, you buy them back for $0.50 and give the 100 shares back to the original owner keeping the profit.

In the U.S., in order to sell stocks short, the seller must arrange for a broker-dealer to confirm that it is able to make delivery of the shorted securities. This is referred to as a "locate", and it is a legal requirement that U.S. regulated broker-dealers not permit their customers to short securities without first obtaining a locate. Brokers have a variety of means to borrow stocks in order to facilitate locates and make good delivery of the shorted security.

The vast majority of stocks borrowed by U.S. brokers come from loans made by the leading custody banks and fund management companies (see list below). Sometimes, brokers are able to borrow stocks from their customers who own "long" positions. In these cases, if the customer has fully paid for the long position, the broker cannot borrow the security without the express permission of the customer, and the broker must provide the customer with collateral and pay a fee to the customer. In cases where the customer has not fully paid for the long position (meaning, the customer borrowed money from the broker in order to finance the purchase of the security), the broker will not need to inform the customer that the long position is being used to effect delivery of another client's short sale.

Most brokers will only allow retail customers to borrow shares to short a stock if one of their own customers has purchased the stock on margin. Brokers will only go through the "locate" process outside their own firm to obtain borrowed shares from other brokers for their large institutional customers.

Stock exchanges such as the NYSE or the NASDAQ typically give short interest or the Short ratio that gives the number of shares that have been sold short as a % of the total float. Alternatively, these can also be expressed as Short interest ratio or the short ratio which is the number of shares sold short as a % of the average daily volume. These can be useful tools to spot trends in stock price movements.

[sửa] Fees

When a broker facilitates the delivery of a client's short sale, the client is charged a fee for this service, usually a standard commission similar to that of purchasing a similar security. If the short position begins to move against you (rise in price), money will be removed from your cash account and moved to your margin account. If short shares continue to rise in price, and you don't have enough funds in your cash account to cover the position, you'll begin to borrow on margin for this purpose. At that time, you'll also begin to accrue margin interest charges. These will be computed and charged the same as for a regular margin debit. When short selling a stock that pays dividends and the ex-dividend date passes while you are short the stock, the dividend will be deducted from your account. It should also be noted that contrary to standard finance theory, the short seller often does not enjoy the benefits of the proceeds of the short sale to earn interest or reduce outstanding margin amounts. The brokers generally do not pass this benefit on to the retail client, unless the client is very large.

[sửa] Markets

[sửa] Futures and options contracts

When trading futures contracts, being 'short' means having the legal obligation to deliver something at the expiration of the contract, although the holder of the short position may alternately buy back the contract prior to expiration instead of making delivery. Short futures transactions are often used by producers of a commodity to fix the future price of goods they have not yet produced. Shorting a futures contract is sometimes also used by those holding the underlying asset (i.e. those with a long position) as a temporary hedge against price declines. Shorting futures may also be used for speculative trades, in which case the investor is looking to profit from any decline in the price of the futures contract prior to expiration.

An investor can also purchase a put option, giving that investor the right (but not the obligation) to sell the underlying asset (such as shares of stock) at a fixed price. In the event of a market decline, the option holder may exercise these put options, obliging the counterparty to buy the underlying asset at the agreed upon (or "strike") price, which would then be higher than the current quoted spot price of the asset.

[sửa] Currency

To sell currencies short a trader borrows a currency and buys another currency with it. It's important to note that in a currency forward, one always shorts one currency and longs another. Confusion can occur from failure to recognize and understand this point: a contract is always long one thing and short another.

When the exchange rate has changed the trader buys the first currency again; this time he gets more of it, and pay back the loan. Since he got more money than he had borrowed initially, he earns money. Of course, the reverse can also occur.

An example of this is as follows: Let us say a trader wants to trade with the dollar and the Indian rupee currencies. Assume that the current market rate is $1=Rs.50 and the trader borrows Rs.100. With this, he buys $2. If the next day, the conversion rate becomes $1=Rs.51, then the trader sells his $2 and gets Rs.102. He returns Rs.100 and keeps the Rs.2 profit.

One may also take a short position in a currency using futures or options; the preceding method is used to bet on the spot price, which is more directly analogous to selling a stock short.

[sửa] Rủi ro

It is important to note that buying shares and then selling them (called "going long") has a very different risk profile from selling short. In the former case, losses are limited (the price can only go down to zero) but gains are unlimited (there is no limit on how high the price can go). In short selling, this is reversed, meaning the possible gains are limited (the stock can only go down to a price of zero), and the seller can lose more than the original value of the share, with no upper limit. For this reason, short selling is usually used as part of a hedge rather than as an investment in its own right.

Many short sellers place a "stop loss order" with their stockbroker after selling a stock short. This is an order to the brokerage to cover the position if the price of the stock should rise to a certain level, in order to limit the loss and avoid the problem of unlimited liability described above. In some cases, if the stock's price skyrockets, the stockbroker may decide to cover the short seller's position immediately and without his consent, in order to guarantee that the short seller will be able to make good on his debt of shares.

Short selling is sometimes referred to as a "negative income investment strategy" because there is no potential for dividend income or interest income. One's return is strictly from capital gains.

Short sellers must be aware of the potential for a short squeeze. This is a sharp uptick in the price of a stock, caused by large numbers of short sellers covering their positions on that stock. This can occur if the price has risen to a point where these people simply decide to cut their losses and get out. (This may occur in an automated way if the short sellers had previously placed stop-loss orders with their brokers to prepare for this eventuality.) Since covering their positions involves buying shares, the short squeeze causes an ever further rise in the stock's price, which in turn may trigger additional covering. Because of this, most short sellers restrict their activities to heavily traded stocks, and they keep an eye on the "short interest" levels of their short investments. Short interest is defined as the total number of shares that have been sold short, but not yet covered.

On occasion, a short squeeze is deliberately induced. This can happen when a large investor (a company or a wealthy individual) notices significant short positions, and buys many shares, with the intent of selling the position at a profit to the short sellers who will be panicked by the initial uptick.

Short sellers have to deliver the securities to their broker eventually. At that point they will need money to buy them, so there is a credit risk for the broker. To reduce this, the short seller has to keep a margin with the broker.

Finally, short sellers must remember that they are betting against the overall upward direction of the market. This, combined with interest costs, can make it unattractive to keep a short position open for a long duration.

[sửa] Strategies

[sửa] Hedge funds

Short selling by hedge funds frequently represents only one leg of a more complex set of transactions which fall into a broad range of investment strategies (see hedge fund).

[sửa] Against the box

One variant of selling short involves a long position. "Selling short against the box" is holding a long position on which one enters a short sell order. The term box alludes to the days when a safe deposit box was used to store (long) shares. The purpose of this technique is to lock in paper profits on the long position without having to sell that position (and possibly incur taxes if said position has appreciated). Whether prices increase or decrease, the short position balances the long position and the profits are locked in (less brokerage fees and short financing costs).

U.S. investors considering entering into a "short against the box" transaction should be aware of the tax consequences of this transaction. Unless certain conditions are met, the IRS deems a "short against the box" position to be a "constructive sale" of the long position, which is a taxable event. These conditions include a requirement that the short position be closed out within 30 days of the end of the year and that the investor must hold their long position, without entering into any hedging strategies, for a minimum of 60 days after the short position has been closed.

[sửa] Opinions

Short sellers have a negative reputation to some. Some businesses campaign against short sellers who target them, sometimes resulting in litigation. Sometimes short sellers have been accused of naked shorting by selling blocks of shares that they do not own.

Advocates of short sellers say that the practice is an essential part of the price discovery mechanism. They state that short-seller scrutiny of companies' finances has led to the discovery of instances of fraud which were glossed over or ignored by investors who had held the companies' stock long. Some hedge funds and short sellers claimed that the accounting of Enron and Tyco was suspicious, months before their respective financial scandals emerged.

Such noted investors as Seth Klarman and Warren Buffett have said that short sellers help the market. Klarman argued that short sellers are a useful counterweight to the widespread bullishness on Wall Street,[3] while Buffett believes that short sellers are useful in uncovering fraudulent accounting and other problems at companies.[4]

[sửa] The regulatory response

Responding to concerns over short-selling, the U.S. Securities and Exchange Commission (SEC) instituted an uptick rule in reaction to the Crash of 1929. The rule provides that a short seller cannot sell a stock short unless on an uptick or a zero-plus tick; this means the stock can only be sold short if the last non-zero "tick" (i.e. trade price) was higher than the preceding one. In doing so, U.S. market regulators are trying to make sure that short sellers are not, by themselves, causing the price depreciation, and that downwards pressure on the stock price is balanced by new buying demand.

In the U.S., Initial Public Offerings (IPOs) cannot be sold short for a month after they start trading. This mechanism is in place to ensure a degree of price stability during a company's initial trading period. However, some penny stock brokerages (also known as bucket shops) have used the lack of short selling during this month to pump and dump thinly traded IPOs. Canada and other countries do allow selling IPOs (including U.S. IPOs) short.

Regulation SHO was the SECs first update to short selling restrictions since 1938. It established "locate" and "close-out" requirements for broker-dealers, in an effort to curb naked short selling. Compliance with the regulation began on January 3, 2005. [5]

In October 2003, the SEC announced a one year pilot program to suspend the uptick rule for 1000 listed and NASDAQ traded stocks selected from the 3000 most liquid securities.[1]

[sửa] Một vài doanh nghiệp cho nhà môi giới, người kinh doanh chứng khoán vay chứng khoán

  • State Street Corporation (Boston)
  • JP Morgan Chase (New York)
  • Citibank (New York)
  • Mellon Bank Corp. (Pittsburgh)
  • Bank of New York (New York)
  • The Northern Trust Company (Chicago)
  • Robeco (Netherlands)
  • UBS (Zürich)

[sửa] Xem thêm

  • Repurchase Agreement
  • Securities lending
  • Short ratio
  • Socially responsible investing
  • Manuel P. Asensio
  • Joseph Parnes

[sửa] Liên kết ngoài

[sửa] Tham khảo

  1. Short Sale Constraints And Stock Returns by C.M Jones and O.A. Lamont
  2. Understanding Short Selling - A Primer
  3. Margin of safety (1991), by Seth Klarman. ISBN 0-88730-510-5
  4. 2006 Berkshire Hathaway Annual Meeting Q&A with Warren Buffett
  5. U.S. SEC (April 11, 2005). Division of Market Regulation: Key Points About Regulation SHO.