Remember a few years back, the first time you checked out

Yahoo! Finance? You entered a stock ticker and you'd get boatloads of financial data, charts, analyst rankings, insider-trading records. Being somewhat naive myself back then, the first time I visited Yahoo! Finance I was sure I'd make a killing with all the information the site provided. If only I could figure out how to use it.

No doubt we've all grown a little wiser since then. At the same time, literally hundreds of Web sites dish out the same general-interest data on stocks that

Yahoo!

(YHOO)

helped pioneer. But over the last couple of years, a new breed of financial Web site has emerged. These sites let you examine companies through more specialized lenses -- everything from rumors, to detailed institutional holdings, to key trades made by insiders.

Buy on the Rumor

Take rumors, for example. Several sites make rumors their stock in trade. One of the most popular is the free site

WhisperNumber.com. Enter a ticker symbol and see what so-called whisper number, or rumored earnings figure, is being bandied about for a particular stock.

These days, of course, companies face great pressure to come in above Street estimates or risk having their stocks hammered. So whisper numbers have become increasingly important. Are the site's numbers accurate? Not always. The site gets its information by using proprietary data-mining software, and it claims an accuracy rate of 74%. But the fact that WhisperNumber.com is probably the most widely cited online source for earnings-estimate rumors means the site's pronouncements take on some importance in their own right -- just as analyst upgrades and downgrades do.

After finding out the whisper number, you could look back at a particular company's previous quarters at a site like

Quicken.com (also free). Just enter a ticker, click on "Analysts Estimates," and scroll down to the line that reads "Qtrly Earnings." Has the company consistently come out with positive or negative earnings surprises? If so, you could expect that pattern to continue. But you could also expect that information to be priced into the stock already -- meaning, if the company breaks the trend either positively or negatively when the actual announcement occurs, look for the stock to move strongly, either up or down.

Several other Web sites traffic in rumors.

Stock Rumors.com (subscription rate, $10 monthly) is worth mentioning because, unlike a lot of its competitors, it publishes how rumors aired on the site have affected a stock's performance. For example, late last October, the site announced that freight forwarder

Air Express International

was shopping for a buyer. When the company confirmed the rumors, its stock quickly rose from 25 to over 30. Sure enough, on Nov. 15, the company announced merger plans with the privatizing German post office,

Deutsche Post AG

. The European shipper paid $1.14 billion, or $33 a share.

JAGfn.com (subscriptions, $10 monthly), a competitor of

TSC

, also publishes daily rumors about companies.

The Fly on the Wall, another popular rumor mill, charges $50 a month for the service but offers a free two-week trial.

Sell on the News

News can often move stocks, too, of course. But news only works to your advantage if you're among the first to know it. If you're day trading and real-time news is important to how you trade, there's really no substitute for the kind of real-time content provided by

Dow Jones Business News

. Expect to pay about $29 a month or more, however. The service is available as an add-on through some online brokers, as well as financial data providers such as

eSignal and

DTN.IQ.

On the other hand, if you're burrowing around looking for background information on companies, try doing a keyword search at

CNNfn's

IndustryWatch . I like

CNNfn's

search engine because it trolls through numerous daily and weekly newspapers in addition to sifting through

CNN's

own content.

Another site,

TraderBot, lets you do keyword searches of breaking news. The $40 monthly subscription fee also gains you access to the site's real-time stock-screening tool. You can register as an after-hours user, however, and try out the news search engine free after the markets close. Likewise, enter keywords or ticker symbols and receive email news alerts from

CNet for free. And finally (you should know that my motivation here is not to ingratiate myself with my employers),

TheStreet.com

has, over the years, amassed what's probably the Web's best collection of commentaries about companies. Just enter your keywords at the "Search the Site" box on the home page.

All the News That Fits

A couple of other sites do some of the search work for you by delivering specialized news. For example,

Splittrader.com (free) sends out as many as a dozen e-mails daily with news about upcoming stock splits. An online tutorial shows you how to trade stock splits during, say, the announcement phase or when the split actually occurs.

InsiderScores.com (free) will send you e-mail alerts on stocks when company insiders have either bought or sold shares -- or if they intend to do so. Just set up a watch list of companies you want to track, and you'll be among the first to know.

Of course, insiders buy and sell stocks in their companies for a variety of reasons. They might buy as a gesture of support for a company that everyone believes is about to topple. Or they might sell to help pay their kids' college tuition. InsiderScores.com helps you decipher these insider-trading patterns. It looks at past insider moves and determines what effect they had on the company. That helps you judge what effect current trading by these same individuals might have on the company's stock price.

Who's Short and Who's Long

Short-sellers, like insiders, can also influence a stock's price. Short-sellers borrow shares and sell them in the hope of profiting by repurchasing those shares later at a lower price. They help push a stock down when they sell the shares they've borrowed. And they help push prices back up when they buy back their borrowed shares to cover their positions. Information on short selling is reported by the exchanges each month, which means it's a lagging indicator. For

Nasdaq

stocks, go to

ViWes InvestInfo: Short Interest on Nasdaq Stocks. Yahoo! Finance will display the short interest on both Nasdaq and

NYSE

stocks. But ViWes lets you compare up to 12 months worth of data via tables. Some technical analysts believe that a large amount of short interest indicates that the stock is poised to rise. Their reasoning is that short-sellers must eventually cover their positions. You could think of their growing short positions as a backlog of buy orders.

Of course, shareholders who are long a stock will move its price, too, especially if they're institutions and they own huge positions. Enter a ticker symbol at

LionShares.com and you receive a list of the top 15 institutional owners of that stock, along with any changes those institutions have made. The information is taken from the 13F

SEC

filings that institutions must make quarterly. This is a lagging indicator as well. However, sign up for a free trial and you'll be alerted to any recent filings. At press time, the site's organizers were still working out how much they plan to charge.

Mark Ingebretsen is editor-at-large with

Online Investor magazine. He has written for a wide variety of business and financial publications. Currently he holds no positions in the stocks of companies mentioned in this column. While Ingebretsen cannot provide investment advice or recommendations, he welcomes your feedback at

mingebretsen@onlineinvestor.com.