Pump & dumps are indicated by...
1. SPAM EMAIL
A legitimate company will never send you spam email. First of all, spam is illegal. Secondly, all the information that they would need to get out to the public is disseminated though press releases. If they need to make themselves aware to the public, they do it through a number of legitimate campaigns such as advertising, technology fairs and the like.
2.
Sometimes emails received are from a free subscription based touting service. Sign-ups are how these touts get around spam laws. However, the intent is the same: to con you out of your money. These touts are paid by the people intending to dump their stock on you and usually say so in the fine print of their promotions. While their names are constantly changing currently subscriptions are available to StocksGoneWild.com, EpicStockPicks.com and countless others. These sites often tout the same stock and there is a good reason for that. Touts usually own many touting sites and promote under various names in order to give the perception of a wide following for the particular stock they are touting.
MoneyTV with Donald Baillargeon is another touting service paid for by insiders wishing to promote their stock under the perception of a TV interview show. The fact is that these insiders pay to be on this "show" and just about the only place you'll see the interview is on MoneyTV's own website. The insiders will usually disseminate a press release bragging about how they were interviewed on MoneyTV in an effort towards self-importance.
3. THE BACKGROUND OF THE OFFICERS
There's an old saying, "Once a crook, always a crook", and that's why it's always a good idea to see who is running the show at the company. Verify his resume. Most companies at one time, will offer up the qualifications of the President, CEO or other officers. Check his past involvement with public companies and the past performance of that stock. Chances are that if he's been involved with past pump and dumps or other schemes, you're now looking at one that is heading in that direction. Also, it is a good idea to look into court records of the individual(s) involved and their previous companies and see if anyone has been involved in civil or criminal proceedings, especially for fraud.
4. MESSAGE BOARD CONTENT
Yes, forums such as investorshub.com, siliconinvestor.com or the Yahoo Finance Message Boards usually contain contributions from child-like posters who are there for no other reason than to try and convince themselves that they made a good investment. But you can often find the touts or Investor Relations guy posting anonymously trying to keep the pom poms shaking and keeping the naysayers in check. They know that people who are apt to follow spam email or stock touts probably consider these message boards to be research so they want to bluster about their great investment and brag about all the money they are supposedly making. These are the guys who call anybody negative or questioning the company a "paid basher" (there is no such thing) or the ones who claim they have done their "DD" ( due diligence) when there is really none to be done. When you ask what DD they did, they will be vague with their answer or give a non-answer, with a "Because I said so" kind of response. They are also the ones who offer up lame excuses for down days such as naked short selling (does not occur in the penny stock market) or MM (market maker) manipulation. They are also the ones who make bold and baseless predictions like, "This is an easy ten-bagger" (stock price will increase by a multiple of ten).
5. CLAIMS OF BREAKTHROUGHS
Beware if the company claims to be an industry leader (do you really think a penny stock can be a leader in anything except possibly scams?) or has made a breakthrough discovery. A company with legitimate breakthrough technology is unlikely to be promoting itself on the penny stock market and will most likely have funding available to it within a variety of partnerships with major companies. These same companies will not likely be interested in dealing with a penny stock company.
6. PRICE AND VOLUME UPSWING ON NO NEWS
If a stock's trading volume and price per share, show a recent and sudden increase, there is a good chance that the stock is being set up for a pump and dump. Especially if it has been involved in one in the past.
7. FINANCIALS (or lack thereof)
A legitimate company will always make recent financials available, even if it is a penny stock that is not required to file financials with the SEC. And if there are financials are they fabricated? Would a billion dollar company be found within a penny stock?
8. ISSUED AND OUTSTANDING
If nobody will tell you how many shares are out on the street or if that number is disproportionate to the stock price (a billion shares of a stock trading @ one tenth of a penny for example, stay away. Chances are a reverse split is coming and you will be left with only a few shares worth a fraction of what you spent.
Source: Interesting article on PumpandDumps.com
