Do large market players using HFT make it unsafe for individual investors to be in the stock market?
There's a lot of hype about HFT. It involves computers doing things that people don't really understand and making a bunch of rich guys a bunch of money, and there was a crisis and so we hate rich wall street guys this year, and so it's a hot-button issue. Meh. There's some reason for concern about the safety of the markets, but I think there's also a lot more of people trying to sell you a newspaper. Remember that while HFT may mean there are a lot of trades, the buying and the selling add up to the same thing. Meanwhile, people who buy stock to hold on to it for significant periods of time will still affect the quantity of stock out there on the market, applying pressure to the price, buying and selling at the prices that they think the security is worth.  As a result, it's unlikely that high-frequency trading moves the stock price very far from the price that the rest of the market would determine for very long; if it did, the lower-frequency traders could take advantage of it, buying if it's too low and selling if it's too high. How long do you plan to hold a stock? If you're trying to do day-trading, you might have some trouble; these people are competing with you to do the same thing, and have significant resources at their disposal. If you're holding onto your stock for years on end (like you probably should be doing with most stock) then a trivial premium or discount on the price probably isn't going to be a big deal for you. "I don't think that HFT is a game-changer for retail investors. It does mean that amateur daytraders need to pack it up and go home, because the HFT guys are smarter, faster and have more money than you. I'm no Warren Buffet, but I've done better in the market over the last 4 years than I ever have, and I've been actively investing since 1995. You need to do your research and understand what you're investing in. Barring outliers like the ""Flash Crash"", nothing has changed. You have a great opportunity to buy quality companies with long track records of generous dividends right now for the ""safe"" part of your portfolio. You have great value stock opportunities. You have great opportunities to take risks on good companies the will benefit from economic recovery. What has changed is that the ""set it and forget it"" advice that people blindly followed from magazines doesn't work anymore. If you expect to park your money in Index funds and don't manage your money, you're going to lose. Remember that saying ""Buy low, sell high""? You buy low when everyone is freaked out and you hear Gold commercials 24x7 on the radio." Obviously there are good answers about the alternatives to the stock market in the referenced question.  HFT has been debated heavily over the past couple of years, and the Flash crash of May 6, 2010, has spurred regulators to rein in heavy automated trading. HFT takes advantage of churn and split second reactions to changing market trends, news and rumors. It is not wise for individual investors to fight the big boys in these games and you will likely lose money in day trading as a result. HFT's defender's may be right when they claim that it makes the market more liquid for you to get the listed price for a security, but the article points out that their actions more closely resemble the currently illegal practice of front-running than a negotiated trade where both parties feel that they've received a fair value. There are many factors including supply and demand which affect stock prices more than volume does. While market makers are generating the majority of volume with their HFT practices, volume is merely the number of shares bought and sold in a day. Volume shows how many shares people are interested in trading, not the actual underlying value of the security and its long term prospects. Extra volume doesn't affect most long term investments, so your long term investments aren't in any extra danger due to HFT. That said, the stock market is a risky place  whether panicked people or poorly written programs are trading out of control. Most people are better off investing rather than merely trading. Long term investors don't need to get the absolute lowest price or the highest sell. They move into and out of positions based on overall value and long term prospects. They're diversified so bad apples like Enron, etc. won't destroy their portfolio. Investors long term view allows them to ignore the effects of churn, while working like the tortoise to win the race while the hare eventually gets swallowed by a bad bet. There are a lot of worrying and stressful uncertainties in the global economy. If it's a question of wisdom, focus on sound investments and work politically (as a citizen and shareholder) to fix problems you see in the system. In some senses, any answer to this question is going to be opinion based - nobody outside of HFT firms really know what they do, as they tend to be highly secretive due to the competitive nature of the activity they're engaged in. What's more, people working at HFT firms are bound by confidentiality agreements, so even those in the industry have no idea how other firms operate. And finally, there tend to be very, very few people at each firm who have any kind of overall picture of how things work. The hardware and software that is used to implement HFT is 'modular', and a developer will work on a single component, having no idea how it fits into a bigger machine (a programmer, for instance, might right routines to perform a function for variable 'k', but have absolutely no idea for what 'k' stands!) Keeping this in mind and returning to the question . . . The one thing that is well known about HFT is that it is done at incredibly high speeds, making very small profits many thousands of times per day. Activities are typically associated with market making and 'scalping' which profits from or within the bid-ask spread. Where does all this leave us? At worst, the average investor might get clipped for a few cents per round trip in a stock. Given that investing buy its very nature involves long holding periods and (hopefully) large gains, the dangers associated with the activities of HFT are negligible for the average trader, and can be considered no more than a slight markup in execution costs. A whole other area not really touched upon in the answers above is the endemic instability that HFT can bring to entire financial markets. HFT is associated with the provision of liquidity, and yet this liquidity can vanish very suddenly at times of market stress as the HFT remove themselves from the market; the possibility of lack of liquidity is probably the biggest market-wide danger that may arise from HFT operations.
I disagree.  First off the SEC is under-funded anyhow, and most economists agree that there needs to be better regulation of the exchanges; ya know since it can fucking crash our economy and send us into WW3.  Secondly, it's a flat Transaction tax much like any other State Sales Tax.  State Sales Tax is arguably the most successful form of taxation there is, b/c it's so damn easy to implement, and so damn easy to audit.  You're blowing this thing way out of proportion.  They require the markets to charge a Transaction tax, and then they do periodic audits to ensure each exchange is doing it.  The rates go up or down based on the previous quarters number of HFTs.  Outside of said formula, this transaction rate can be altered by a meeting of a few SEC heads, and approved when approved by the appropriate congressional body.  Kills 2 birds with one stone:  * more money to the underfunded SEC * lessens the impact of HFTs and turns the markets back into a market instead of a casino.  It will have minimal effects on buy &amp; hold traders since they typically research for a long time, then buy &amp; hold stock for many months.    It will mainly affect those who buy &amp; unload several times per day.    PS:  If you think that letting a market die and having new ones pop up periodically is a good idea then holy shit.  Financial markets need stability &amp; regulation.  Finance doesn't like uncertainty.  Crash &amp; burn marketplaces will help no one, and will raise uncertainty which we all know investors hate. The opening price is derived from new information received. It reflects the current state of the market. Opening Price Deviation (from Investopedia): Investor expectation can be changed by corporate announcements or   other events that make the news. Corporations typically make   news-worthy announcements that may have an effect on the stock price   after the market closes. Large-scale natural disasters or man-made   disasters such as wars or terrorist attacks that take place in the   afterhours may have similar effects on stock prices. When this   happens, some investors may attempt to either buy or sell securities   during the afterhours. Not all orders are executed during after-hours trading. The lack of   liquidity and the resulting wide spreads make market orders   unattractive to traders in after-hours trading. This results in a   large amount of limit or stop orders being placed at a price that is   different from the prior day’s closing price. Consequently, when the   market opens the next day, a substantial disparity in supply and   demand causes the open to veer away from the prior day’s close in the   direction that corresponds to the effect of the announcement, news or   event. "This is a very important question and you will find arguments from both sides, in part because it is still understudied. Ben Golub, Economics Ph.D., from Stanford answers ""Is high-frequency trading good for the economy?"" on Quoram quite well.  This is an important but understudied question. There are few   published academic studies on it, though several groups are working on   the subject. You may be interested in the following papers: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1569067 http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1361184 These document some of the phenomena that arise in high frequency   trading, from a theoretical and an empirical perspective. However, a   full equilibrium analysis of the unique features of high frequency   trading is still missing, and until it is done, all our answers will   be kind of  tentative. Nevertheless, there are some obvious things one can say. Currently,   high frequency traders are competing to locate physically closer and   closer to exchanges, because milliseconds matter. Thus, large amounts   of money are being spent to beat other market makers by tiny fractions   of a second. Once many firms make these investments, the market looks   like it did before in terms of competition and prices, but is a tiny   bit faster. This investment is unlikely to be socially efficient: that   is, the users of  the market don't actually benefit from the fact that   their trades are executed half a millisecond faster -- certainly not   enough to cover all the investment that went into making that happen. Some people who study the issue believe that high frequency trading   (HFT) actually exacerbates market volatility; some plots to this   effect are found in the second paper linked above. There is certainly   no widely accepted theory that says faster trading technology   necessarily increases efficiency, and it is easy to think of   algorithms that can make money (at least in the short run) but hurt   most other investors, as well as the informational value of the   market. One caution is that some of the complaining about HFT comes from those   who lose when HFT gets better -- old-style market makers. They   certainly have an incentive to make HFT out to be very bad. So some   complaints about the predatory nature of HFT should be taken with a   grain of salt. There is no strong economic consensus about the value   of this activity. For what it's worth, my personal impression is that   this is more bad than good. I'll post an update here as more   definitive research comes out. You can also find a debate on High-frequency trading from the Economist which gives both sides of the argument. In conclusion: Regardless of how you feel about HFT it seems like it's here to stay and won't be leaving in the foreseeable future. So the debate will rage on... Additional resource you may finding interesting: Europe Begins Push To Ban HFT High Frequency Trading Discussion On CNBC Should High Frequency Trading (HFT) be banned ?" "private investors that don't have the time or expertise for active investment.  This may be known as every private investor. An index fund ensures average returns. The bulk of active trading is done by private institutions with bucketloads of experts studying the markets and AI scraping every bit of data it can get (from the news, stock market, the weather reports, etc...). Because of that, to get above average returns an average percent of the time, singular private investors have to drastically beat the average large team of individuals/software. Now that index ETF are becoming so fashionable, could there be a tipping point at which the market signals that active investors send become so diluted that this ""index ETF parasitism"" collapses? How would this look like and would it affect only those who invest in index ETF or would it affect the stock market more generally? To make this question perhaps more on-topic: Is the fact (or presumption) that index ETF rely indirectly on active investment decisions by other market participants, as explained above, a known source of concern for personal investment? This is a well-covered topic. Some people think this will be an issue.   Others point out that it is a hard issue to bootstrap. I gravitate to this view. A small active market can support a large number of passive investors. If the number of active investors ever got too low, the gains & likelihood of gains that could be made from being an active investor would rise and generate more active investors. Private investing makes sense in a few cases. One example is ethics. Some people may not want to be invested, even indirectly, in certain companies." "Generally, yes.  Rather than ask, ""why are these guys so cheap?"", you should be asking why the big names are so expensive. :) Marketing spend plays a big role there. Getting babies to shill for your company during the super bowl requires a heck of a lot of commissions. Due to the difficulties involved in setting up a brokerage, it's unlikely that you'll see a scam. A brokerage might go bankrupt for random reasons, but that's what investor insurance is for. ""Safeness"" is mostly the likelihood that you'll be able to get access to your funds on deposit with the broker. Investment funds are insured by SIPC for up to $500,000, with a lower limit on cash. The specific limits vary by broker, with some offering greater protection paid for on their own dime. Check with the broker -- it's usually on their web pages under ""Security"". Funds in ""cash"" might be swept into an interest-earning investment vehicle for which insurance is different, and that depends on the broker, too. A few Forex brokers went bankrupt last year, although that's a new market with fewer regulatory protections for traders. I heard that one bankruptcy in the space resulted in a 7% loss for traders with accounts there, and that there was a Ponzi-ish scam company as well. Luckily, the more stringent regulation of stock brokerages makes that space much safer for investors. If you want to assess the reliability of an online broker, I suggest the following: It's tempting to look at when the brokerage was founded. Fly-by-night scams, by definition, won't be around very long -- and usually that means under a few months. Any company with a significant online interface will have to have been around long enough to develop that client interface, their backend databases, and the interface with the markets and their clearing house. The two brokerages you mentioned have been around for 7+ years, so that lends strength to the supposition of a strong business model. That said, there could well be a new company that offers services or prices that fit your investment need, and in that case definitely look into their registrations and third-party reviews. Finally, note that the smaller, independent brokerages will probably have stiffer margin rules. If you're playing a complex, novel, and/or high-risk strategy that can't handle the volatility of a market crash, even a short excursion such as the 2010 flash crash, stiff margin rules might have consequences that a novice investor would rather pretend didn't exist." Yes, this is a way to avoid the pattern day trader regulation. The only downside being that your broker will have different commission rates and your capital will be split amongst several places. Generally not, however some brokers may allow it. My previous CFD Broker - CMC Markets, used to allow you to adjust the leverage from the maximum allowed for that stock (say 5%) to 100% of your own money before you place a trade. So obviously if you set it at 100% you pay no interest on holding open long positions overnight. If you can't find a broker that allows this (as I don't think there would be too many around), you can always trade within your account size. For example, if you have an account size of $20,000 then you only take out trades that have a face value up to the $20,000. When you become more experienced and confident you can increase this to 2 or 3 time your account size. Maybe, if you are just starting out, you should first open a virtual account to test your strategies out and get used to using leverage. You should put together a trading plan with position sizing and risk management before starting real trading, and you can test these in your virtual trading before putting real money on the table. Also, if you want to avoid leverage when first starting out, you could always start trading the underlying without any leverage, but you should still have a trading plan in place first. This is the exactly wrong thing to do especially in the age of algorithmic trading.  Consider this event from 2010:  Chart Source  Another similar event occurred in 2015 and there was also a currency flash crash in that year. As you can see the S&P 500 (and basically the entire market) dropped nearly 7% in a matter of minutes.  It regained most of that value within 15 minutes. If you are tempted to think that 7% isn't that big of a deal, you need to understand that specific securities will have a much bigger drop during such events.  For example the PowerShares S&P 500 Low Volatility ETF (SPLV) was down 45% at one point on Aug 24, 2015 but closed less than 6% down. Consider what effect a stop loss order would have on your portfolio in that circumstance.  You would not be able to react fast enough to buy at the bottom.  The advantage of long-term investing is that you are immune to such aberrations. Additionally, as asked by others, what do you do once you've pulled out your money.  Do you wait for a big jump in the market and hop back in?  The risk here is that you are on the sidelines for the gains.  By missing out on just a small number of big days, you can really hurt your long-term returns.