请教如何做空

[nightingale]

国内股票市场无做空机制， 本人无任何做空经验。 不知哪位高手肯赐教。 另外， margin 账户 是什么意思， 开margin 帐户的条件是什么？

 

[dkwan]

margin is playing leverage.

Say, if its not a margin account, the ratio is 1:1, means you use $1 to buy $1 worth of stock.
If its a 1% margin, the ratio is 1:100, means you use $1 to buy $100 worth of stock.

Example:
Non-margin: Invested: $1000, owned $1/stock, you own 1000 shares. If each share up $1, you make $1000. Rate of return is 100% ( $1000 profit / $1000 invested )

Margin: Invested $10, owned $1/stock, you own 1000 shares. If each share up $1, you make $1000. Rate of return is 10000% ( $1000 profit / $10 invested ).

Usually the requirment is to have some cushion. Example: $10000 in the account, you can only invest $5000. or experinced trader could trade up to $10000, and in case of lost money. They need to cover the lost before you can hold on to those shares, or you have to liquided them

 

[nightingale]

Thank you so much for replying my message.You are talking about buying stocks on margin. Is it the same when selling stocks on margin? Do es it follow the same rule, or there is any other requirement?any books you suggust to read?

 

[nightingale]

I found an article about margin trading, here it is :Margin:Borrowing Money To Pay for Stocks"Margin" is borrowing money from your broker to buy a stock and using your investment as collateral. Investors generally use margin to increase their purchasing power so that they can own more stock without fully paying for it. But margin exposes investors to the potential for higher losses. Here's what you need to know about margin.Understand How Margin Works Let's say you buy a stock for $50 and the price of the stock rises to $75. If you bought the stock in a cash account and paid for it in full, you'll earn a 50 percent return on your investment. But if you bought the stock on margin – paying $25 in cash and borrowing $25 from your broker – you'll earn a 100 percent return on the money you invested. Of course, you'll still owe your firm $25 plus interest.The downside to using margin is that if the stock price decreases, substantial losses can mount quickly. For example, let's say the stock you bought for $50 falls to $25. If you fully paid for the stock, you'll lose 50 percent of your money. But if you bought on margin, you'll lose 100 percent, and you still must come up with the interest you owe on the loan. In volatile markets, investors who put up an initial margin payment for a stock may, from time to time, be required to provide additional cash if the price of the stock falls. Some investors have been shocked to find out that the brokerage firm has the right to sell their securities that were bought on margin – without any notification and potentially at a substantial loss to the investor. If your broker sells your stock after the price has plummeted, then you've lost out on the chance to recoup your losses if the market bounces back.Recognize the RisksMargin accounts can be very risky and they are not suitable for everyone. Before opening a margin account, you should fully understand that:• You can lose more money than you have invested; • You may have to deposit additional cash or securities in your account on short notice to cover market losses; • You may be forced to sell some or all of your securities when falling stock prices reduce the value of your securities; and • Your brokerage firm may sell some or all of your securities without consulting you to pay off the loan it made to you. You can protect yourself by knowing how a margin account works and what happens if the price of the stock purchased on margin declines. Know that your firm charges you interest for borrowing money and how that will affect the total return on your investments. Be sure to ask your broker whether it makes sense for you to trade on margin in light of your financial resources, investment objectives, and tolerance for risk.Read Your Margin AgreementTo open a margin account, your broker is required to obtain your signature. The agreement may be part of your account opening agreement or may be a separate agreement. The margin agreement states that you must abide by the rules of the Federal Reserve Board, the New York Stock Exchange, the National Association of Securities Dealers, Inc., and the firm where you have set up your margin account. Be sure to carefully review the agreement before you sign it.As with most loans, the margin agreement explains the terms and conditions of the margin account. The agreement describes how the interest on the loan is calculated, how you are responsible for repaying the loan, and how the securities you purchase serve as collateral for the loan. Carefully review the agreement to determine what notice, if any, your firm must give you before selling your securities to collect the money you have borrowed.Know the Margin RulesThe Federal Reserve Board and many self-regulatory organizations (SROs), such as the NYSE and NASD, have rules that govern margin trading. Brokerage firms can establish their own requirements as long as they are at least as restrictive as the Federal Reserve Board and SRO rules. Here are some of the key rules you should know:Before You Trade – Minimum MarginBefore trading on margin, the NYSE and NASD, for example, require you to deposit with your brokerage firm a minimum of $2,000 or 100 percent of the purchase price, whichever is less. This is known as the "minimum margin." Some firms may require you to deposit more than $2,000.Amount You Can Borrow – Initial MarginAccording to Regulation T of the Federal Reserve Board, you may borrow up to 50 percent of the purchase price of securities that can be purchased on margin. This is known as the "initial margin." Some firms require you to deposit more than 50 percent of the purchase price. Also be aware that not all securities can be purchased on margin.Amount You Need After You Trade – Maintenance MarginAfter you buy stock on margin, the NYSE and NASD require you to keep a minimum amount of equity in your margin account. The equity in your account is the value of your securities less how much you owe to your brokerage firm. The rules require you to have at least 25 percent of the total market value of the securities in your margin account at all times. The 25 percent is called the "maintenance requirement." In fact, many brokerage firms have higher maintenance requirements, typically between 30 to 40 percent, and sometimes higher depending on the type of stock purchased.Here's an example of how maintenance requirements work. Let's say you purchase $16,000 worth of securities by borrowing $8,000 from your firm and paying $8,000 in cash or securities. If the market value of the securities drops to $12,000, the equity in your account will fall to $4,000 ($12,000 - $8,000 = $4,000). If your firm has a 25 percent maintenance requirement, you must have $3,000 in equity in your account (25 percent of $12,000 = $3,000). In this case, you do have enough equity because the $4,000 in equity in your account is greater than the $3,000 maintenance requirement.But if your firm has a maintenance requirement of 40 percent, you would not have enough equity. The firm would require you to have $4,800 in equity (40 percent of $12,000 = $4,800). Your $4,000 in equity is less than the firm's $4,800 maintenance requirement. As a result, the firm may issue you a "margin call," since the equity in your account has fallen $800 below the firm's maintenance requirement.Understand Margin Calls – You Can Lose Your Money Fast and With No NoticeIf your account falls below the firm's maintenance requirement, your firm generally will make a margin call to ask you to deposit more cash or securities into your account. If you are unable to meet the margin call, your firm will sell your securities to increase the equity in your account up to or above the firm's maintenance requirement.Always remember that your broker may not be required to make a margin call or otherwise tell you that your account has fallen below the firm's maintenance requirement. Your broker may be able to sell your securities at any time without consulting you first. Under most margin agreements, even if your firm offers to give you time to increase the equity in your account, it can sell your securities without waiting for you to meet the margin call.Ask Yourself These Key Questions• Do you know that margin accounts involve a great deal more risk than cash accounts where you fully pay for the securities you purchase? Are you aware you may lose more than the amount of money you initially invested when buying on margin? Can you afford to lose more money than the amount you have invested?• Did you take the time to read the margin agreement? Did you ask your broker questions about how a margin account works and whether it's appropriate for you to trade on margin? Did your broker explain the terms and conditions of the margin agreement?• Are you aware of the costs you will be charged on money you borrow from your firm and how these costs affect your overall return?• Are you aware that your brokerage firm can sell your securities without notice to you when you don't have sufficient equity in your margin account?Learn More About Margin TradingFor more information, visit the website of NASD and read Investing with Borrowed Funds: No "Margin" for Error, which links to other articles, statistics, and resources on margin trading. Investor Tips: Margin - Borrowing Money To Pay for Stocks

 

[nightingale]

sorry, the article looks terrible.

 

[nightingale]

also found a website for day trading:FINRA - Investor Information - Day Trading Margin Requirements: Know the Rules
信息仅供参考， 风险自负

 

[挺傻]

简单说几句关于MARGIN和作空的问题。

1.开户的时候建议开MARGIN账户。那是因为股票卖后不需要等几天的交易SETTLE,你就可以马上用卖掉股票的资金进行新的买卖。但是并不建议你马上就用MARGIN进行操作。
一般来说，美国开户会给你和你股票资金数额相同的一倍MARGIN。也就是说你会有两倍的PURCHASING POWER。这个如果你用好了当然可以扩大收益，但是如果你的股票下跌了，你又用MARGIN了，你自己的本金马上就不符合一半的要求，你会收到MARGIN CALL。你的证券商会要求你在一个时间内马上卖出你的部分股票弥补本金的不足，那个时候如果你的股票跌的比较惨，你会有很大损失。你也有四倍MARGIN的可能，但是那个基本是要求你必须当天平仓的，基本DAY TRADING　才用。所以原则是如果你刚开始做少用MARGIN，起码不能全用。
100的MARGIN那个是外汇交易才用的。

2.SHORT股票就是说你对某个股票看跌。在股票瞬间上涨时，你从你的交易商那里借到这个股票卖出，然后等它跌了以后你再买回还给你的交易商。不是所有的股票都是卖空，要看你交易商那里你是否可以借到。SHORT股票一定要设很TIGHT的STOP，因为如果股票上涨你的损失可能是无限的。没有MARGIN账户不能SHORT。牛市中慎重SHORT，尤其是强势股票。
如果你没SHORT经验，最好先看少做。很多做的很成功的牛人都是从来不SHORT股票的。能够两边来回做的人要对市场的感觉非常好才行。

 

[挺傻]

你那个链接是SEC对于DAY TRADING的限制。连续五个交易日内你如果进行了四次及以上的当天买卖同一种股票，就会被认定是DAY TRADER。这样你会有DAY TRADING POWER,就是四倍的那个MARGIN。同时你的账户要有25000以上的EQUITY不然你不能进行DAY TRADING操作。
不过那个基本是对美国账户的要求。
我听几个朋友说他们也DAY TRADE了不过他们账户也没要求那么多BALANCE，不知道是不是加拿大的规定不一样。你最好去问你的BROKER。

 

[nightingale]

多谢版主

 

[lucky boy]

In a margin account,
get a margin call for purchase= (1- initial margin)/(1-maintenance margin)
for short sale=(1+initial margin)/(1+maintenance margin)