Stock Quotes in this Article: ARNA, HMA, THC

 BALTIMORE (Stockpickr) -- Put down the 10-K filings and the stock screeners. It’s time to take a break from the traditional methods of generating investment ideas – instead, let the crowd do it for you.

From hedge funds to individual investors, scores of market participants are turning to social media to figure out which stocks are worth watching. It’s a concept that’s known as “crowdsourcing”, and it uses the masses to identify emerging trends in the market. Crowdsourcing has long been a popular tool for the advertising industry, but it also makes a lot of sense as an investment tool. After all, the market is completely driven by the supply and demand, so it can be valuable to see what names are trending among the crowd.

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While some fund managers are already trying to leverage social media resources like Twitter to find algorithmic trading opportunities, for most investors, crowdsourcing works best as a starting point for investors who want a starting point in their analysis. Today, we’ll leverage the power of the crowd to take a look at some of the most active stocks on the market today.

These “most active” names are the most heavily-traded names on the market – and often, uber-active names have some sort of a technical or fundamental catalyst driving investors’ attention on shares. And when there’s a big catalyst, there’s often a trading opportunity.

Without further ado, here’s a look at three health-care-related stocks that are seeing a lot of action today.

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Tenet Healthcare

Nearest Resistance: $5.50

Nearest Support: $5.06

Catalyst: Supreme Court Healthcare Ruling

Meanwhile, shares of Tenet Healthcare (THC) are up big today -- around 8.4% as of this writing -- following the Supreme Court’s ruling upholding the constitutionality of Obamacare. Regardless of where you sit politically on the issue, the ruling has big implications for firms like Tenet.

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That's because Tenet, which operates healthcare facilities, should benefit from the ruling because it means that more consumers will be covered under health insurance. That should help to reduce write-offs for unpaid services and send more patients voluntarily through the firm’s doors.

Tenet is trading in a wide range in today’s session as a result of the Supreme Court ruling. Resistance at $5.50 is fairly weak. That could open the door to higher ground for shares of THC in the next few sessions.

Arena Pharmaceuticals

Nearest Resistance: $11.90

Nearest Support: $8.90

Catalyst: Obesity Drug Approval

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Wall Street is going to be watching Arena Pharmaceuticals (ARNA) closely today -- CEO Jack Lief will be ringing the closing bell of the Nasdaq this afternoon, celebrating FDA approval of the firm’s obesity drug Belviq. The news came out yesterday, sending shares nearly 30% higher after investors found out that ARNA would own the first weight loss drug approved in 13 years.

Shares of Arena are trading in a very wide range, retracing around 7% today as profit takers exit the stock. With support and resistance so far apart in this stock, I’d recommend staying at the sidelines until ARNA can exit its consolidation phase.

Arena shows up on a recent list of Hot Biotech StocksTraded by Hedge Funds.

Health Management Associates

Nearest Resistance: $7.50

Nearest Support: $6.60

Catalyst: Supreme Court Healthcare Ruling

Hospital operator Health Management Associates (HMA) is another name that’s getting upward momentum from the Supreme Court ruling on Obamacare. Shares of the firm are up more than 7% in today’s session, driving the stock to a new six-month high.

Making new highs is significant from an investor psychology standpoint because it means that everyone who has bought shares in the last year is sitting on gains. As a result, the “back to even” mentality is less of a concern than it would be for a name with a higher proportion of shareholders sitting on losses.

For late-to-the-game buyers though, I’d recommend waiting until HMA pushes above today’s high water mark before diving in.

To see these stocks in action, check out the at Most-Active Stocks portfolio on Stockpickr.

-- Written by Jonas Elmerraji in Baltimore.

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At the time of publication, author had no positions in stocks mentioned.

Jonas Elmerraji, based out of Baltimore, is the editor and portfolio manager of the Rhino Stock Report, a free investment advisory that returned 15% in 2008. He is a contributor to numerous financial outlets, including Forbes and Investopedia, and has been featured in Investor's Business Daily, in Consumer's Digest and on MSNBC.com.