Why is a stock trade flat on large volume?
Large volume just means a lot of market participants believe they know where the stock price will be (after some amount of time).  The fact that the price is not moving just means that about 50% of those really confident traders think the stock will be moving up, and about 50% of those really confident traders think the stock will be moving down.
That's true. So instead, they brute force the exchange with buy orders before they know if there's even any demand for the equity. Most of these get cancelled.  If they see someone else placing a large buy order, they let theirs go through and do not cancel. They meet the ask and get the order because they don't care about getting the best deal.   The buy order the HFT sent through is for the entire book. The HFT can then demand the highest price possible. After that, they dump the unsought portion of the book back into the market.  Regulation have cracked down on this practice. However, that just means HFT have decided to build their own exchanges.  The HFT buy order was placed before they even knew there was anyone else looking for the same buy. The most likely explanation is that the calls are being bought as a part of a spread trade.  It doesn't have to be a super complex trade with a bunch of buys or sells. In fact, I bought a far out of the money option this morning in YHOO as a part of a simple vertical spread.  Like you said, it wouldn't make sense and wouldn't be worth it to buy that option by itself. "You are interpreting things wrong.  Indian Infotech and Software Ltd (BOM:509051) clearly has volume and trades.  The MoneyControl site says  Your words like ""Nobody is selling the stock"" and ""no trade going on"" are completely unfounded." "I've alway thought that it was strange, but the ""price"" that gets quoted on a stock exchange is just the price of the last transaction. The irony of this definition of price is that there may not actually be any more shares available on the market at that price. It's also strange to me that the price isn't adjusted at all for the size of the transaction. A transaction of just 1 share will post a new price even if just seconds earlier 100,000 shares traded for a different price. (Ok, unrealistic example, but you get my point.) I've always believed this is an odd way to describe the price. Anyway, my diatribe here is supposed to illustrate the point that the fluctuations you see in price don't really reflect changing valuations by the stock-owning public. Each post in the exchange maintains a book of orders, with unmatched buy orders on one side and unmatched sell orders on the other side. If you go to your broker and tell him, ""fill my order for 50,000 shares at market price"", then the broker won't fill you 50,000 shares at .20. Instead, he'll buy the 50 @ .22, then 80 @ .23, then 100 @ .30, etc. Because your order is so large compared to the unmatched orders, your market order will get matched a bunch of the unmatched orders on the sell side, and each match will notch the posted price up a bit. If instead you asked the broker, ""open a limit order to buy 50000 shares at .20"", then the exchange will add your order to the book: In this case, your order likely won't get filled at all, since nobody at the moment wants to sell at .20 and historically speaking it's unlikely that such a seller will suddenly appear. Filling large orders is actually a common problem for institutional investors: http://www.businessweek.com/magazine/content/05_16/b3929113_mz020.htm http://www.cis.upenn.edu/~mkearns/papers/vwap.pdf (Written by a professor I had in school!)" I'd think that liquidity and speed are prioritized (even over retail brokers and in come cases over PoP) for institutional traders who by default have large positions.  When the going gets tough, these guys are out and the small guys - trading through average retail brokers - are the ones left holding the empty bag. All the time. For high volume stocks, it may be tough to see exactly what's going on, e.g. the bid/ask may be moving faster than your connection to the broker can show you.  What I've observed is with options. The volume on some options is measured in the 10's or 100's of contracts in a day. I'll see a case where it's $1.80/$2.00 bid/ask, and by offering $1.90 will often see a fill at that price. Since I may be the only trade on that option in the 15 minute period and note that the stock wasn't moving more than a penny during that time, I know that it was my order that managed to fill between the bid/ask. I've never seen a dividend, split or other corporate action during the day, but I have seen trade suspended a few times when something big happened. The market opening price is not in general the same as the close of the previous day. It can gap up or down and does frequently. I don't know of an api to find out if the dividend was cash or stock, but stock dividends are a lot less common. 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. "For stock options, where I'm used to seeing these terms: Volume is usually reported per day, whereas open interest is cumulative. In addition, some volume closes positions and some opens positions.  For example, if I am long one contract and sell it to someone who was short one contract, then that adds to volume and reduces open interest.  If I hold no contracts and sell (creating a short position) to someone who also had no contracts, then I add to volume and I increase open interest. EDIT: With the clarification in your comment, then I would say some people opened and closed positions in that one day.  Their opening and closing trades both contribute to ""volume"" but they have not net position in the ""open interest.""" Something to consider is that in the case of the company you chose, on the OTC market, that stock is thinly traded and with such low volume, it can be easy for it to fluctuate greatly to have trades occur.  This is why volume can matter for some people when it comes to buying shares. Some OTC stocks may have really low volume and thus may have bigger swings than other stocks that have higher volume. It may have some value!  Investopedia has a well-written quick article on how stock holders may still get some portion of the liquidated assets.  While there is generally little left for common shareholders if the price of those shares is tiny and some money does come back to shareholders there can still be significant profit to be made. As to why the trading volume is so high... there are many firms and hedge funds that specialize in calculating the value of and buying distressed debt and stock.  They often compete with each other to by the stock/debt that common shareholders are trying to get rid of.  In this particular case, there is a lot of popular interest, intellectual property at stake and pending lawsuits that probably boosts volume. "When you look at those results you'll see that it lists the actual market cap for the stocks.  The ones on the biggest price move are usually close the the $1B capitalization cut-off that they use. (The don't report anything with less than $1B in capitalization on these lists.)  The ones on the biggest market cap are much larger companies. So, the answer is that a 40% change in price on a company that has $1B capitalization will be a $400M change in market cap.  A 4% change on a company with $100B capitalization will be a $4B change in market cap.  The one that moved 40% will make the ""price"" list but not the market cap list and vice versa." It could be an endless number of reasons for it.  It could simply just be a break through a long term resistance causing technical traders to jump in.  It could be an analyst putting out a buy recommendation.  If fundamentals have not changed then maybe the technicals have changed. Momentum could have reached an oversold position causing new buyers to enter the market. Without knowing the actual stock, its fundamentals and its technicals, no one will ever know exactly why. 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 First--and I'm only repeating what has been said already--roboadvisors are a great way to avoid paying high MERs and still not have to do much yourself. The Canadian Couch Potato method is great IF you are disciplined and spend the time every few months to regularly re-balance your portfolio. However, any savings you gain in low MERs is going to very likely be lost if you aren't re-balancing or if you aren't patient and disciplined in your investing. For that reason, the Couch Potato way isn't appropriate for 97% of the general population in my opinion. But if you are reading this, you probably already aren't a member of the general population. For myself, life seems always too busy and I've got a kid on the way. I see a huge value in using a robo-advisor (or alternatively Tangerine) and saving time in my day. The next question, which robo-advisor is best? I did a bunch of research here and my conclusion is that they are all fairly similar. My final three came down to Wealthbar/Wealthsimple/NestWeatlh. Price structures vary, but minus a few dollars here or there, there isn't a lot of difference in costs. What made WealthSimple stick out was that they provide some options for US citizens that help me prevent tax headaches. They also got back to me by email with really detailed answers when I had questions, which was really appreciated. Their site and monthly updates are minimalist and intuitive to navigate. Great user experience all around (I do web design myself). My gut feeling is that they have their act together and will stick around as a company for a long while.