RIP-OFF ALERT: Clark has a trio of Ponzi scheme stories to share with you today.

First, The Wall Street Journal reports $250 million was swiped in an investment scheme to sell telecommunications services to Las Vegas casinos. The promoters convinced those who didn't have money to refinance their homes and cash out in order to buy into this "can't lose" opportunity. People were wiped out, many of them senior citizens.

In this particular scam, the promoters would buy lists of people who were 50 and older from data-mining companies and then invite them to investment seminars. People would turn over their life savings and lose it all.

"Rather than having a comfortable retirement like we thought we'd have," one senior told The Wall Street Journal, "we're living pension check to pension check."

The second Ponzi scheme involved a fellow who stole $52 million from people by promising returns of 35 percent every 90 days in other investments, according to The Los Angeles Times.

Now, stop for a moment and consider this: Savings is earning around two percent. Stocks typically return nine or 10 percent in good cycles. So how in the world could anything return 35 percent every 90 days?!

The Los Angeles Times also had a separate story about another scam that netted $35 million from people. In this one, unsuspecting investors were told they would earn monthly returns of 14 percent paid out ever quarter by getting into government-guaranteed loans.

Here's what you should know: "Can't lose" opportunities promising more than nine or 10 percent are either unbelievably risky or completely a scam. If you want "safe," stick with bank CDs and money market funds.

And finally, don't buy what you don't understand!