Does high frequency trading (HFT) punish long-term investment?
No, at least not noticeably so. The majority of what HFT does is to take advantage of the fact that there is a spread between buy and sell orders on the exchange, and to instantly fill both orders, gaining relatively risk-free profit from some inherent inefficiencies in how the market prices stocks. The end result is that intraday trading of the non-HFT nature, as well as speculative short-term trading will be less profitable, since HFT will cause the buy/sell spread to be closer than it would otherwise be. Buying and holding will be (largely) unaffected since the spread that HFT takes advantage of is miniscule compared to the gains a stock will experience over time.  For example, when you go to buy shares intending to hold them for a long time, the HFT might cost you say, 1 to 2 cents per share. When you go to sell the share, HFT might cost you the same again. But, if you held it for a long time, the share might have doubled or tripled in value over the time you held it, so the overall effect of that 2-4 cents per share lost from HFT is negligible. However, since the HFT is doing this millions of times per day, that 1 cent (or more commonly a fraction of a cent) adds up to HFTs making millions. Individually it doesn't affect anyone that much, but collectively it represents a huge loss of value, and whether this is acceptable or not is still a subject of much debate! I disagree strongly with the other two answers posted thus far. HFT are not just liquidity providers (in fact that claim is completely bogus, considering liquidity evaporates whenever the market is falling). HFT are not just scalping for pennies, they are also trading based on trends and news releases. So you end up having imperfect algorithms, not humans, deciding the price of almost every security being traded. These algorithms data mine for news releases or they look for and make correlations, even when none exist.  The result is that every asset traded using HFT is mispriced. This happens in a variety of ways. Algos will react to the same news event if it has multiple sources (Ive seen stocks soar when week old news was re-released), algos will react to fake news posted on Twitter, and algos will correlate S&P to other indexes such as VIX or currencies. About 2 years ago the S&P was strongly correlated with EURJPY. In other words, the American stock market was completely dependent on the exchange rate of two currencies on completely different continents. In other words, no one knows the true value of stocks anymore because the free market hasnt existed in over 5 years. "Not really. High frequency traders affect mainly short term investors. If everyone invested long-term and traded infrequently, there would be no high frequency trading. For a long term investor, you by at X, hold for several years, and sell at Y. At worst, high frequency trading may affect ""X"" and ""Y"" by a few pennies (and the changes may cancel out). For a long term trader that doesn't amount to a ""hill of beans"" It is other frequent traders that will feel the loss of those ""pennies."""
"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." The stock market's principal justification is matching investors with investment opportunities.  That's only reasonably feasible with long-term investments.  High frequency traders are not interested in investments, they are interested in buying cheap and selling expensive.  Holding reasonably robust shares for longer binds their capital which is one reason the faster-paced business of dealing with options is popular instead.  So their main manner of operation is leeching off actually occuring investments by letting the investors pay more than the recipients of the investments receive. By now, the majority of stock market business is indirect and tries guessing where the money goes rather than where the business goes. For one thing, this leads to the stock market's evaluations being largely inflated over the actual underlying committed deals happening.  And as the commitment to an investment becomes rare, the market becomes more volatile and instable: it's money running in circles. Fast trading is about running in front of where the money goes, anticipating the market.  But if there is no actual market to anticipate, only people running before the imagination of other people running before money, the net payout converges to zero as the ratio of serious actual investments in tangible targets declines. By and large, high frequency trading converges to a Ponzi scheme, and you try being among the winners of such a scheme.  But there are a whole lot of people competing here, and essentially the net payoff is close to zero due to the large volumes in circulation as opposed to what ends up in actual tangible investments. It's a completely different game with different rules riding on the original idea of a stock market.  So you have to figure out what your money should be doing according to your plans. "Are you talking long-term institutional or retail investors? Long-term *retail* investors look for *orderly markets*, the antithesis of HFT business models, which have a direct correlation between market volatility and profits. To a lesser extent, some ""dumb money""/""muppet"" institutionals do as well. HFT firms tout they supply liquidity into markets, when in fact the opposite is true.  Yes, HFTs supply liquidity, *but only when the liquidity's benefits runs in their direction*. That is, they are applying the part of the liquidity definition that mentions ""high trading activity"", and conveniently ignoring the part that simultaneously requires ""*easily* buying *or* selling an asset"".  If HFT's are the new exchange floor, then they need to be formalized as such, *and become bound to market maker responsibilities*. If they are actually supplying liquidity, like real Designated Market Makers in the NYSE for example, they become responsible to supply a specified liquidity for specified ticker symbols in exchange for their informational advantage on those tickers. The indisputable fact is that HFT cannot exist at their current profit levels without the information advantage they gain with preferential access to tick-by-tick data unavailable to investors who cannot afford the exchange fees ($1M per exchange 10 years ago, more now). Restrict the entire market, including HFTs, to only second-by-second price data without the tick-by-tick depth, and they won't do so well.  Don't get me wrong, I'm not knocking HFTs *per se*; I think they are a marvelous development, so long as they really do ""supply liquidity"". Right now, they aren't doing so, and especially in an orderly manner. If you want retail investors to keep out of the water as they are doing now, by all means let HFT (and regulatory capture, and a whole host of other financial service industry ills) run as they are. There are arguments to be made about ""only let the professionals play the market"", where there is no role for retail and anyone who doesn't know how to play the long-term investment game needs to get out of the kitchen. But if you are making such an argument, come out and say so." I dont think you understand teh main problem with HFT, they locate the machines next to the exchanges, and make money based on the latency between exchanges. This is not something anyone but them can do. And it is basically cheating the market.  You ever see the scam.. it was in mash, where [Frank Burns](http://www.funtrivia.com/en/subtopics/M*A*S*H----Out-of-Sight-Out-of-Mind-181978.html) got the radio signals early for the games, and would place bets on the games already knowing the outcome for when they were broadcast on official armed forces radio. That is what HFC is. They get the score of the game before you do, and then bet on the game.  and yes they place a lot of orders and cancel them, that isnt to slow other traders but to force more latency on the system, so they can know the scores even earlier. HFT doesn't increase correlations nor do hedge funds, If you look at the euro crisis, correlations have skyrocketed, then in late december jan and feb during the rally the correlations started subsiding and specific risk started taking over, crisis mode increases correlations. &gt; 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.  This is the part I never understand. If a short term tax doesn't affect buy &amp; hold traders, when why would HFT affect buy &amp; hold traders? By exploiting institutional investors, HFT does hurt small investors. People with pension, mutual, and index funds get smaller returns. Endowment funds are also going to get hurt which hurts hospitals, schools, charities, and other institutions that work for the public good.  I agree with you though. At this point we would likely be just arguing semantics. It's not necessarily the case that HFT acts as a tax on small traders. I haven't seen any studies demonstrating that HFT increases the average cost of shares; if anything small investors will be largely unaffected by HFT as it will be random noise to them, sometimes creating a slight increase, sometimes a slight decrease. The people most affected by HFT are institutional investors, whom HFT desks are pretty good at predicting the order pattern of and hence exploiting. They have no interest or capacity to exploit the small guys. 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. There is no reason that HFT in itself should be illegal. It provides a significant advantage to companies with access to those automated systems but then, we might as well eschew NASDAQ and go back to the manually traded days of NYSE or ban day trading in favor of long-term investing.  What is problematic is that they place and immediately cancel large number of orders for two reasons - to test the market and to slow down the competition.  A proposed ~~tax~~fee to charge for cancellation of non-executed trades seems like an interesting solution. "A lot of people have already explained that your assumptions are the issue, but I'll throw in my 2¢. There are a lot of people who do the opposite of long term investing.  It's called high frequency trading.  I'd recommend reading the Wikipedia article for more info, but very basically, high frequency traders use programs to determine which stocks to buy and which ones to sell. An example program might be ""buy if the stock is increasing and sell if I've held it more than 1 second.""" "You're not making any sort of a persuasive argument why predatory HFT should be allowed to levy a tax on the system. Yes, computer trading is heck of a lot better than paper trading. You're citing an article from 2010 that states things I'm not even arguing against as somehow supporting this ""tax"", the mechanisms of which the author was not even aware of at the time.   There is no valid argument for why this tax is necessary or good for anyone but the firms profiting from it. I'm all for lower spreads and near instant order processing, but that doesn't excuse some greedy prick from scalping my 401k a point or two of compounding interest every year." "If you're investing for the long term your best strategy is going to be a buy-and-hold strategy, or even just buying a few index funds in several major asset classes and forgetting about it. Following ""market conditions"" is about as useful to the long term trader as checking the weather in Anchorage, Alaska every day (assuming that you don't live in Anchorage, Alaska). Let me suggest treating yourself to a subscription to The Economist and read it once a week. You'll learn a lot more about investing, economics, and world trends, and you won't be completely in the dark if there are major structural changes in the world (like gigantic housing bubbles) that you might want to know about." Not really. This just shows you might be able to fill huge orders a little less cheaply now, but then somebody else gets to fill it at a better price and the HFT/Market Maker took on some risk for some profit. That's pretty much the definition of providing liquidity. How is this raising prices? It's not. Raising prices would be if HFT bought like 2mil worth of stock and just held it for some time, then tried to sell it to you later at a better price, but that's just investing. "First it is worth noting the two sided nature of the contracts (long one currency/short a second) make leverage in currencies over a diverse set of clients generally less of a problem.  In equities, since most margin investors are long ""equities"" making it more likely that large margin calls will all be made at the same time. Also, it's worth noting that high-frequency traders often highly levered make up a large portion of all volume in all liquid markets ~70% in equity markets for instance.  Would you call that grossly artificial?  What is that volume number really telling us anyway in that case? The major players holding long-term positions in the FX markets are large banks (non-investment arm), central banks and corporations and unlike equity markets which can nearly slow to a trickle currency markets need to keep trading just for many of those corporations/banks to do business.  This kind of depth allows these brokers to even consider offering 400-to-1 leverage.  I'm not suggesting that it is a good idea for these brokers, but the liquidity in currency markets is much deeper than their costumers."