Is there a way to monitor when executives or leaders in a company sell off large holdings?
Exec Insiders have to file with the SEC and some sites like secform4.com track it. But many insiders have selling programs where the sell the same amount every month or quarter so you would have to do your homework to determine if there are real signals in the activity. SEC Form 3 and SEC Form 4 are filed when insiders make share/derivatives acquisitions, transfers, sells and buys There is a time limit AFTER the action where they can be filed, such as 12 business days, so this can be a substantial amount of time after the effect on the market, depending on your strategy. You can aggregate these forms from SEC sources or from third party websites and services. In some cases, types of insider trading are permissible at certain intervals, so if you learn about when certain shares become unlocked, you can try to predict what insider actions will be and share price movements around those times.
A public company should have a link for investor relations, which should help provide a trail of basis if this is a matter of company buyout, takeover, etc.  This gets you close, but if you don't have an exact date, it will just be close, not exact.  One clean way out of this, assuming the goal is to get rid of the stock and move on, is to donate the shares to charity. You will take the present value as a deduction, and be done. You can use a charitable gift fund such as those offered by Schwab or Fidelity, so if say, the shares are worth $20K, and you typically donate $5K per year, the fund lets you do this transaction at once, then send to the charities you wish over the next few years. This would be a nice Raspberry Pi project for Mathematica, which comes bundled free on the Raspbian OS. You can program it up and leave it running.  It's not expensive and doesn't use much power. A program to monitor stock prices or volume could be written as simply as :-  This checks the volume of trades of Oct 2014 US crude oil futures every 30 seconds and sends an email if the volume jumps by more than 100. The financial data in this example is curated from Yahoo.  If specific data is not available or not updated frequently enough, if you can find an alternative online data source it's usually possible read the data in.  For example, this is apparently real-time data :- {Crude Oil, 92.79, -0.67, -0.71%} After leaving the above program running while writing this the volume of trades has risen like so :-  Edit I just set this running on a Raspberry Pi.  I had to use gmail for the email setup as described in this post: Configuring Mathematica to send email from a notebook.  Anyway, it's working.  Hope I don't get inundated with emails. ;-) "My Broker and probably many Brokers provide this information in a table format under ""Course of Sale"". It provides the time, price and volume of each trade on that day. You could also view this data on a chart in some charting programs. Just set the interval to ""Tick by Tick"" and look at the volume. ""Tick by Tick"" will basically place a mark for every trade that is taken and then the volume will tell you the size of that trade." "What if everyone decided to sell all the shares at a given moment, let's say when the stock is trading at $40? I imagine supply would outweigh demand and the stock would fall. Yes this is the case. Every large ""Sell"" order results in price going down and every large ""Buy"" order results in price going up. Hence typically when large orders are being executed, they are first negotiated outside for a price and then sold at the exchange. I am not talking about Ownership change event. If a company wants a change in ownership, the buyer would be ready to pay a premium over the market price to get controlling stake." No matter how a company releases relevant information about their business, SOMEBODY will be the first to see it. I mean, of all the people looking, someone has to be the first. I presume that professional stock brokers have their eyes on these things closely and know exactly who publishes where and when to expect new information. In real life, many brokers are going to be seeing this information within seconds of each other. I suppose if one sees it half a second before everybody else, knows what he's looking for and has already decided what he's going to do based on this information, he might get a buy or sell order in before anybody else. Odds are that if you're not a professional broker, you don't know when to expect new information to be posted, and you probably have a job or a family or like to eat and sleep now and then, so you can't be watching somebody's web site constantly, so you'll be lagging hours or days behind the full-time professionals. Of course. The fact that it's such a generic concern should be taken for granted - that's why I think the article focuses on it too much. Everybody knows that losing a lot of executives is bad news, even if there was no line in the 10-K at all. So I'd have preferred to see less about that and more information on what it could mean for this company specifically. "Unfortunately, there is very little data supporting fundamental analysis or technical analysis as appropriate tools to ""time"" the market. I will be so bold to say that technical analysis is meaningless. On the other hand, fundamental analysis has some merits. For example, the realization that CDOs were filled with toxic mortgages can be considered a product of fundamental analysis and hence provided traders with a directional assumption to buy CDSs. However, there is no way to tell when there is a good or bad time to buy or sell. The market behaves like a random 50/50 motion. There are many reasons for this and interestingly, there are many fundamentally sound companies that take large dips for no reason at all. Depending on your goal, you can either believe that this volatility will smooth over long periods and that the market has generally positive drift. On the other hand, I feel that the appropriate approach is to remain active. You will be able to mitigate the large downswings by simply staying small and diversifying  - not in the sense of traditional finance but rather looking for uncorrelated products. Remember, volatility brings higher levels of correlation. My second suggestion is to look towards products like options to provide a method of shaping your P/L - giving up upside by selling calls against a long equity position is a great example. Ground your trades with fundamental beliefs if need be, but use your tools and knowledge to combat risks that may create long periods of drawdown." Some personal finance packages can track basis cost of individual purchase lots or fractions thereof. I believe Quicken does, for example. And the mutual funds I'm invested in tell me this when I redeem shares. I can't vouch for who/what would make this visible at times other than sale; I've never had that need. For that matter I'm not sure what value the info would have unless you're going to try to explicitly sell specific lots rather than doing FIFO or Average accounting. Bloomberg is really just a huge database.  You can look up just about anything you need to know.  Launchpad is much better than the old NW market monitors.  The Excel API is useful.  If it wasn't where all my brokers are I would consider something different like Eikon.  It has some limitations but it's a useful system and parts of my job would be a pain without it. Many exchanges trade the same securities.  An order may be posted to a secondary exchange, but if the National Best Bid and Offer data provider malfunctions, only those with data feeds from that exchange will see it. Only the data provider for the primary exchange where a stock is listed provides the NBBO. Missing orders are very common with the NBBO data providers.  NASDAQ's order consolidator has had many failures over the past few years, and the data provider's top executive has recently resigned. Brokers have no control over this system.  A broker may be alerted to a malfunction by an accountholder, but a broker may only inform the relevant exchange and the relevant data provider. In general you cannot. Once the security is no longer listed on the exchange - it doesn't have to provide information to the exchange and regulators (unless it wants to be re-listed). That's one of the reasons companies go private - to keep their (financial and other) information private. If it was listed in 1999, and is no longer listed now - you can dig through SEC archives for the information. You can try and reach out to the company's investors' relations contact and see if they can help you with the specific information you're looking for. "There are a number of ways to measure such things and they are generally called ""sentiment indicators"".  The ones that I have seen ""work"", in the sense that they show relatively high readings near market tops and relatively low readings near market bottoms.  The problem is that there are no thresholds that work consistently.  For example, at one market top a sentiment indicator may read 62.  At the next market top that same indicator might read 55.  So what threshold do you use next time?  Maybe the top will come at 53, or maybe it will not come until 65. There was a time when I could have listed examples for you with the names of the indicators and what they signaled and when.  But I gave up on such things years ago after seeing such wide variation.  I have been at this a long time (30+ years), and I have not found anything that works as well as we would like at identifying a top in real time.  The best I have found (although it does give false signals) is a drop in price coupled with a bearish divergence in breadth.  The latter is described in ""Stan Weinstein's Secrets For Profiting in Bull and Bear Markets"". Market bottoms are a little less difficult to identify in real time.  One thing I would suggest if you think that there is some way to get a significant edge in investing, is to look at the results of Mark Hulbert's monitoring of newsletters.  Virtually all of them rise and fall with the market and almost none are able to beat buy and hold of the Wilshire 5000 over the long term." I don't think that you will be able to find a list of every owner for a given stock. There are probably very few people who would know this. One source would be whoever sends out the shareholder meeting mailers.  I suspect that the company itself would know this, the exchange to a lesser extent, and possibly the brokerage houses to a even lesser extent. Consider these resources: Investment banks will put out various reports and collect revenues from that along with their banking activity.  I don't read them or care to read them myself.  If banks can make money from something, they will likely do it, especially if it is legal. To take the Tesla stock question for a moment: Aren't you ruling out that yesterday was the day that Tesla was included in the Nasdaq 100 and thus there may be some people today exiting because they tried to cash in on the index funds having to buy the stock and bid it up in a sense?  Or as @littleadv points out there could be those tracking the stocks not in the index that would have been forced to sell for another idea here. The Goldman note is a possible explanation but there could well be more factors in play here such as automated trading systems that seek to take advantage of what could be perceived as arbitrage opportunities. There can be quick judgments made on things which may or may not be true in the end.  After all, who knows exactly what is causing the sell-off.  Is it a bunch of stop orders being triggered?  Is it people actually putting in sell order manually?  Is it something else?  There are lots of questions here where I'm not sure how well one can assign responsibility here. "any major brokerage firm will have something like this. more speculative rumors will typically not make their way to the ""news"" there, though; the news feeds are from established wires, who don't report on those things until confirmed."