What is the cause of sudden price spikes in the FOREX market?
If you do not understand the volatility of the fx market, you need to stop trading it, immediately. There are many reasons that fx is riskier than other types of investing, and you bear those risks whether you understand them or not. Below are a number of reasons why fx trading has high levels of risk: 1) FX trades on the relative exchange rate between currencies. That means it is a zero-sum game. Over time, the global fx market cannot 'grow'. If the US economy doubles in size, and the European economy doubles in size, then the exchange rate between the USD and the EUR will be the same as it is today (in an extreme example, all else being equal, yes I know that value of currency /= value of total economy, but the general point stands).  Compare that with the stock market - if the US economy doubles in size, then effectively the value of your stock investments will double in size. That means that stocks, bonds, etc. tied to real world economies generally increase when the global economy increases - it is a positive sum game, where many players can be winners. On the long term, on average, most people earn value, without needing to get into 'timing' of trades. This allows many people to consider long-term equity investing to be lower risk than 'day-trading'. With FX, because the value of a currency is in its relative position compared with another currency, 1 player is a winner, 1 player is a loser. By this token, most fx trading is necessarily short-term 'day-trading', which by itself carries inherent risk. 2) Fx markets are insanely efficient (I will lightly state that this is my opinion, but one that I am not alone in holding firmly). This means that public information about a currency [ie: economic news, political news, etc.] is nearly immediately acted upon by many, many people, so that the revised fx price of that currency will quickly adjust. The more efficient a market is, the harder it is to 'time a trade'. As an example, if you see on a news feed that the head of a central bank authority made an announcement about interest rates in that country [a common driver of fx prices], you have only moments to make a trade before the large institutional investors already factor it into their bid/ask prices. Keep in mind that the large fx players are dealing with millions and billions of dollars; markets can move very quickly because of this. Note that some currencies trade more frequently than others. The main currency 'pairs' are typically between USD and / or other G10 country-currencies [JPY, EUR, etc.]. As you get into currencies of smaller countries, trading of those currencies happens less frequently. This means that there may be some additional time before public information is 'priced in' to the market value of that currency, making that currency 'less efficient'. On the flip side, if something is infrequently traded, pricing can be more volatile, as a few relatively smaller trades can have a big impact on the market.  3) Uncertainty of political news. If you make an fx trade based on what you believe will happen after an expected political event, you are taking risk that the event actually happens. Politics and world events can be very hard to predict, and there is a high element of chance involved [see recent 'expected' election results across the world for evidence of this]. For something like the stock market, a particular industry may get hit every once in a while with unexpected news, but the fx market is inherently tied to politics in a way that may impact exchange rates multiple times a day. 4) Leveraging. It is very common for fx traders to borrow money to invest in fx. This creates additional risk because it amplifies the impact of your (positive or negative) returns. This applies to other investments as well, but I mention it because high degrees of debt leveraging is extremely common in FX. To answer your direct question: There are no single individual traders who spike fx prices - that is the impact you see of a very efficient market, with large value traders, reacting to frequent, surprising news.  I reiterate: If you do not understand the risks associated with fx trade, I recommend that you stop this activity immediately, at least until you understand it better [and I would recommend personally that any amateur investor never get involved in fx at all, regardless of how informed you believe you are]. It depends on the currency pair since it is much harder to move a liquid market like Fiber (EURUSD) or Cable (GBPUSD) than it is to move illiquid markets such as USDTRY, however, it will mostly be big banks and big hedge funds adjusting their positions or speculating (not just on the currency or market making but also speculating in foreign instruments). I once was involved in a one-off USD 56 million FX trade without which the hedge fund could not trade as its subscriptions were in a different currency to the fund currency. Although it was big by their standards it was small compared with the volumes we expected from other clients.  Governments and big companies who need to pay costs in a foreign currency or receive income in one will also do this but less frequently and will almost always do this through a nominated bank (in the case of large firms).  Because they need the foreign currency immediately; if you've ever tried to pay a bill in the US denominated in Dollars using Euros you'll know that they aren't widely accepted. So if I need to pay a large bill to a supplier in Dollars and all I have is Euros I may move the market. Similarly if I am trying to buy a large number of shares in a US company and all I have is Euros I'll lose the opportunity. Forex is really not that volatile compared to other major asset classes like stocks and commodities. But still markets are generally unencumbered in the major pairs and therefore spikes in volatility can happen. Take what happened with the Swiss Franc a few years ago for example, or GBPUSD recently with news of Brexit. This is less the case with highly regulated currencies like the Chinese Yuan (CNY) Volatility is caused by excessive buy or sell pressure in relation to the available liquidity at the current price. This is usually caused by large buy or sell orders placed with interbank desks by institutions (often including other banks) and central banks. News can also sometimes have a dramatic impact and cause traders to adjust their prices significantly and very quickly.
The volume required to significantly move the price of a security depends completely on the orderbook for that particular security. There are a variety of different reasons and time periods that a security can be halted, this will depend a bit on which exchange you're dealing with. This link might help with the halt aspect of your question: https://en.wikipedia.org/wiki/Trading_halt I'm not an economics expert or anything, but what seems strange to me is the randomising part. Everything else looks fine but why does it randomly select the next item for price increase, wouldn't this depend on supply/demand and the players in the game? "No one is quite sure what happened (yet).  Speculation includes: The interesting thing is that Procter & Gamble stock got hammered, as did Accenture.  Both of which are fairly stable companies, that didn't make any major announcements, and aren't really connected to the current financial instability in Greece.  So, there is no reason for there stock prices to have gone crazy like that.  This points to some kind of screw up, and not a regular market force. Apparently, the trades involved in this event are going to be canceled. Edit #1: One thing that can contribute to an event like this is automatic selling triggered by stop loss orders.  Say someone at Citi makes a mistake and sells too much of a stock.  That drives the stock price below a certain threshold.  Computers that were pre-programmed to sell at that point start doing their job.  Now the price goes even lower.  More stop-loss orders get triggered.  Things start to snowball.  Since it's all done by computer these days something like this can happen in seconds.  All the humans are left scratching their heads. (No idea if that's what actually happened.) Edit #2: IEEE Spectrum has a pretty concise article on the topic.  It also includes some links to follow. Edit #3 (05/14/2010): Reuters is now reporting that a trader at Waddell & Reed triggered all of this, but not through any wrongdoing. Edit #4 (05/18/2010): Waddell & Reed claims they didn't do it.  The House Financial Services Subcommittee investigated, but they couldn't find a ""smoking gun"".  I think at this point, people have pretty much given up trying to figure out what happened. Edit #5 (07/14/2010): The SEC still has no idea.  I'm giving up. :-)" "On a longer time scale, the plot thickens:  It almost looks random.  A large drop in real rates in the mid-70s, a massive spike in the early 80s, followed by a slow multi-decade decline. The chaos doesn't seem to be due to interest rates.  They steadily climbed and steadily fell:  All that's left is inflation:  First, real rates should be expected to pay a moderate rate, so nominal rates will usually be higher than inflation. However, interest rates are very stable over long time periods while inflation is not.  Economists call this type of phenomenon ""sticky pricing"", where the price, interest rates in this case, do not change much despite the realities surrounding them. But the story is a little more complicated. In the early 1970s, Nixon had an election to win and tried to lessen the impacts of recession by increasing gov't spending, not raising taxes, and financing through the central bank, causing inflation.  The strategy failed, but he was reelected anyways.   This set the precedent for the hyperinflation of the 1970s that ended abruptly by Reagan at the beginning of his first term in the early 1980s.  Again, interest rates remained sticky, so real rates spiked. Now, the world is not growing, almost stagnating.  Demand for equity is somewhat above average, but because corporate income is decelerating, and the developed world's population is aging, demand for investment income is skyrocketing.   As demand rises, so does the price, which for an investor is a form of inverse of the interest rate. Future demand is probably best answered by forecasters, and the monetarist over and undertones still dominating the Federal Reserve show that they have finally learned after 100 years that inflation is best kept ""low and stable"":  But what happens if growth in the US suddenly spikes, inflation rises, and the Federal Reserve must sell all of the long term assets it has bet so heavily on quickly while interest rates rise?  Inflation may not be intended, but it is not impossible." Contrary to Muro's answer which strangely shows a graph of the Fed's balance sheet and not the money supply, the supply of US dollars has never doubled in a few days.  This graph from Wikipedia shows M2, which is the wider measure of money supply, to have doubled over approximately 10 years, http://en.wikipedia.org/wiki/File:Components_of_US_Money_supply.svg The answer to whether gold has a higher chance of experiencing big devaluation has to do with forces outside anyone's control, if a big new mine of gold is discovered that could affect prices, but also if the economy turns around it could lead investors to pull out of gold and back into the stock markets. The USD, on the other hand, is under control of the policy makers at the Fed who have a dual mandate to keep inflation and unemployment low. The Fed seems to have gotten better over the last 30 years at controlling inflation and the dollar has not experienced big inflation since the 70s. Inflation, as measured by Core CPI, has been maintained at less than 4% for the last 20 years and is currently coming off record low levels below 1%. One interpretation of the above is that Pound (alongside US Dollar, Euro and other major curriencies), which forms the Forex basket of countries has dropped to less than 10% weightage in case of China's Forex holding. Now the question is where did this money go, this money probably have gone into Forex market to buy Yuan against Pound/Dollar etc. to bolster or strengthen Yuan. The currency reserve management is the 'wealth' management part and the 'currency' management part is what is known as 'central bank intervention' to stabilize the currency. A market correction has been expected for several weeks. It happens all the time, but people need an excuse to panic. Sometimes, I think panic is their usual state and they just look for fuel to keep it going because they can't handle boredom. Summarized article: On Friday, the Dow Jones Industrial Average dropped almost 275 points and wiped out the last of the index's gains for the year.   Friday's massive selloff was triggered by a dismal US jobs report and data indicating a European and Chinese economic slowdown. Friday was the worst day of the year for the market.   Worried investors moved cash to the US Treasury bond market which also dragged the yield to a record low.   Some analysts believe the panic in the market may cause the Federal Reserve to plan for additional stimulus.   Federal Reserve Chairman Ben Bernanke is scheduled to speak next week.   *For more summarized news, subscribe to the [/r/SkimThat](http://www.reddit.com/r/SkimThat) subreddit* If you didn't have a stop loss set (or trailing stop loss) then an equally random spike in the other direction could have obliterated your account and put you in debt to the broker, depending on the terms of that broker, as these are highly leveraged positions. Market anomaly? If your currency bet was unrelated to the fed's interest rate decision today, then you should probably just stop trading. Because you are new to forex trading, you would be wise to trade long-term and not short-term. For example, watch the Daily and Weekly charts for trends, not the 15 Minute and 1 Hour.  Doing this, there is little concern for the best time of day. You will ideally have trades setup many days in advance, just waiting for them to be triggered. It doesn't really matter if you're present or not. If I understand you correctly, you are noticing that a stock's price can change drastically when the time changes from pre-market trading hours to open market hours. This could occur because a much smaller pool of investors make trades during pre-market and after-market hours. When the regular market opens there is a large influx of trades, causing the prices to jump. Slippage is tied to volatility, so when volatility increases the spread will also increase. There is no perfect formula to figure out slippage but from observations, it might make sense to look at the bar size in relation to previous bars to determine slippage (assuming fixed periods). This is because when there is a sudden spike in price, it's usually due to stop order triggering or a news event and those will increase the volatility dramatically in seconds. My guess is that both the blue and pinkish lines are hand drawn by someone. The blue line indicates 'higher lows' while the pinkish line represents 'higher highs'. Together they form a trading channel in which you can expect future prices to be (unless there is some unanticipated event that occurs).  Edit: since the price broke out above the trading channel at the start of the year (and is verified by the increase in volume at that time) something must have occurred to increase the value of the stock.  Edit2: this news likely explains the breakout in price. Edit3: this chart shows that the stock price is now 'seeking equilibrium'. The price will, likely, be volatile over the next few days or weeks. The market is simply gapping at these times, some news may have come out that makes the market gap on the open from its previous close. Being FX, the market in one country might be trading and then at the start of the hour trading in a different country may commence, causing a small gap in price. Generally many things could cause the price to gap up or down, and these gaps sometime can occur at the start of a new hour or other timeframe you are using. They do tend to happen more often at the start of a new day's trading on a daily chart, especially with stocks. Step 1: Get a part-time job in sales.  Perhaps selling appliances at Sears. Step 2: If you are great at that, then look into becoming a stock broker/investment adviser in Boise ... which is a sales job.   Step 3: If you are great at that, then you might be able to become a portfolio manager, perhaps a hedge fund manager for the clients you collected as a stock broker/ investment consultant.   That seems to be the steps I have seen from reading the bios of a number of professional investors.   The other method seems to be an MBA from a top 10 business school.