Lisa Smith 2016年9月27日
择时交易是试图预测未来市场运动的方向以便能进行低买高卖。这是一个许多专业投资者使用并且大多数其他投资者希望复制的策略。有趣的是，这个策略对许多交易者来说也带有消极含义。你是否曾经想过当一个日内交易员赚钱呢？请继续阅读我们关于这个策略的讨论。
争议
在学术层面上，择时交易受到那些相信有效市场理论的人质疑。有效市场理论的前提是在任何时间，单一股票或者市场的价格完全反应所有当前信息。因此，由于没有人能优先于其他人获得信息，所以没有投资者能获得预测回报的优势。
在学术界以外，择时交易的争议主要集中在日内交易的执行是由散户投资者进行的，2003年对冲机构投资者爆出了对冲基金丑闻。这类问题的媒体报道已经非常普遍，以至于许多投资者认为日内交易不是一个可靠的投资策略。因为大众媒体的投资者关注度比学术媒体大很多，择时交易在大众媒体中的形象提供了一个很好的关于这个话题探索的主题。
日内交易站在了传统交易哲学“买入并持有”的对立面。它是一个终极市场时机把握策略。虽然日内交易吸引的所有注意力表明这个理论是可以实现的，但是批评者认为如果这个理论成立，至少一个著名基金经理已经掌握这个系统并会出现类似“巴菲特的日内交易”这样的新闻。
众多已经成为传奇的投资者中没有一个是通过日内交易发家的。即使是使用30分钟到30天交易时间框架的迈克尔·斯坦哈特也表示在进行投资决定时也需要考虑长期视角。从经济角度来看，许多专业的基金经理和金融顾问都会回避日内交易，认为回报不能与风险相匹配。
合法性、道德和共同基金丑闻
刨除争议，择时交易既不违法也不违反道德准则。尝试获利是投资者进行投资的原因，选择你的买卖时机以便能进行低买高卖是大多数投资者的共同目标。
共同基金的问题是他们的择时交易是暗箱操作的，因为对冲基金公司发布的招股说明说上严格禁止短期交易。尽管存在这一禁令，某些特殊客户还是被允许这样做。因此，问题不是出现在交易策略上，而是这一策略不公平和不道德的执行，是因为对客户的区别对待，允许一些人这么做而禁止其他人使用相同的策略。
专业的方法
世界上所有伟大投资者的成功都在某种程度上依赖择时交易。无论他们的买卖交易决定是根据市场的基本面分析、单个公司的技术分析、个人直觉还是所有这些因素，他们成功的最终原因都是在正确的时间做出了正确的交易。在大多数例子中，这些决定的时间都很长而且依赖“买入并持有”策略。
价值投资是一个简单的例子，因为这一策略基于购买那些价格低于内在价值的股票，并在其价值得到市场承认时出售。大多数价值投资者以耐心著称，因为价值被低估的股票价值低估的时间通常会维持很长时间。
进行择时交易还是不进行择时交易？
如果你的目标是低买高卖，那么你就是择时交易者。如上面所说的，短期择时交易要比长期择时交易难的多。普通投资者没有时间（或经历）观察每日市场运动，进行长期投资要比判断每日市场走向要好的多。当考虑到风险和成本，即使是最专业的投资者也更希望尽量延长他们的投资时间周期。无论你持有多久，购买一种投资并持有到价格上涨则比在上午9点买入投资而希望在几个小时之后获利要容易成功的多。
Would You Profit As A Day Trader?
By Lisa Smith | Updated September 27, 2016 — 1:13 PM EDT
Market timing attempts to predict the direction of future market movements in order to buy low and sell high. It is a strategy that most professional investors rely on and most other investors hope to replicate. Interestingly, it's also a strategy that has negative connotations for many investors. Have you ever wondered whether you could make money as a day trader? Read on as we cover the controversy behind this strategy.
The Controversy
At the academic level, the very concept of market timing is called into question by those who believe in the efficient market theory. This theory is based on the premise that, at any given time, prices fully reflect all available information on a particular stock and/or market. Thus, no investor has an advantage in predicting a return on a stock price because no one has access to information not already available to everyone else.
Outside of academia, the controversy surrounding market timing is primarily focused on day trading conducted by individual investors and the mutual fund trading scandals perpetrated by institutional investors in 2003. Media coverage of these issues has been so prevalent that many investors now dismiss market timing as a credible investment strategy. Because the popular media has a significantly greater audience among investors than most academics do, the image the popular media has created for market timing provides a good spot to begin an exploration of the topic.
Day trading sits at the extreme end of the investing spectrum from conventional buy-and-hold wisdom. It is the ultimate market-timing strategy. While all the attention that day trading attracts seems to suggest that the theory is sound, critics argue that, if that were so, at least one famous money manager would have mastered the system and claimed the title of "the Warren Buffet of day trading".
The long list of successful investors that have become legends in their own time does not include a single individual that built his or her reputation by day trading. Even Michael Steinhardt, who made his fortune trading in time horizons ranging from 30 minutes to 30 days, claimed to take a long-term perspective on his investment decisions. From an economic perspective, many professional money managers and financial advisors shy away from day trading, arguing that the reward simply does not justify the risk.
Legality, Ethics and Mutual Fund Scandals
Despite the controversy, market timing is neither illegal nor unethical. Attempting to make a profit is the reason investors invest, and timing your purchases and sales so that you buy low and sell high is the general goal of most investors (although short-selling andarbitrage take a different approach, the success or failure of these strategies still depends on timing).
The problems with mutual fund trading that cast market timing in a negative light occurred because the prospectuses written by the mutual fund companies strictly forbid short-term trading. Despite this prohibition, special clients were allowed to do it anyway. So, the problem was not with the trading strategy but rather with the unethical and unfair implementation of that strategy, which permitted some investors to engage in it while excluding others.
The Professional Approach
All of the world's greatest investors rely, to some extent, on market timing for their success. Whether they base their buy/sell decisions on fundamental analysis of the markets, technical analysis of individual companies, personal intuition, or all of the above, the ultimate reason for their success involves making the right trades at the right time. In most cases, those decisions involve extended periods of time and are based on buy-and-hold investment strategies.
Value investing is a clear example, as the strategy is based on buying stocks that trade for less than their intrinsic values and selling them when their value is recognized in the marketplace. Most value investors are known for their patience, as undervalued stocks often remain undervalued for significant periods of time.
To Time or Not to Time?
If your goal is to buy low and sell high, you are market timing. As noted above, it is very difficult to be successful at short-term market timing over an extended period of time. The average investor doesn't have the time (or desire) to watch the market on a daily basis and will be far better served by a focus on long-term investing instead of trying to guess the direction of the market on a daily basis. When the costs and risks are factored into the equation, even most professional investors prefer to stretch their investment horizons over a longer time frame. It is far easier to be successful if you purchase an investment and hold it until the price rises, regardless of how long it takes, than to purchase an investment at 9am and hope to make a profit just a few hours later.
本文翻译由兄弟财经提供
文章来源：http://www.investopedia.com/articles/trading/07/market-timing.asp?rp=i