MIAMI -- Some South Florida residents are being targeted in a stock buying scam.

It starts with a simple phone call -- a message left on your voice mail: "Hey Steph, it's Wendy. I looked for your old number but couldn't find it but Brandy says this is your new one..." begins the message.

It sounds like someone got the wrong number -- someone with a great hot stock tip: "There's this new company that supposedly developed some zillion dollar cancer testing and it's going to go up big this week."

This seemingly 'innocent' message is actually a calculated scam.

"I could see how the potential for someone to fall prey to it because it was very personal," said Nancy Fountain, who received the message on her cell phone Monday.

Nancy found out on Tuesday that two of her co-workers had also received the message on their home answering machines.

Mary Anne Miller was suspicious from the get-go.

"It was curious that in the middle of the message she said she didn't know what a patent was which made me think 'this can't be real' by the end of the message I was just kind of laughing," Miller said.

It's no laughing matter to the Securities and Exchange Commission.

They call this a "pump and dump" scam. It can be carried out by individuals or organized groups.

What they do is try to push up the price of a company stock with false information.

Once the stock hits a certain price, these scammers will sell off the shares they own... leaving everyone who bought on their bad information holding the bag.

In this latest scam, the company being pushed is a small bio-tech firm called "Power Three Medical."

A record of the company's stock price since June first shows it's been 'pumped up' a few times.

The S.E.C. will try to track down the scammers, but finding them isn't easy because they use calling cards to leave these messages.

The S.E.C. says most important thing is warning the public that these scammers are out there so people don't get stung by this stock scam.

"Its your money they don't care it's your money, they're just looking to profit off innocent people so public be aware, think about what you're doing, don't jump to conclusions," Fountain said

If you've been targeted in a pump-and-dump scheme by phone, email or in an Internet chat room, the S.E.C. wants to hear from you.

Contact them on the web at www.sec.gov, and look for their on line complaint form or call them at (800) SEC-0330.