What a year it’s been for you and your nest egg: Falling home prices and bank interest rates. High unemployment. A stock market bringing on roller-coaster nausea with daily drops and rises of hundreds of points.

See also: Don't make these 5 common financial mistakes.

Tough times make easy pickings for scammers who cheat investors out of some $40 billion a year, with seniors the most common targets. So as we head into a new year, take a cue about the most common investment scams of 2011 as reported by the North American Securities Administrators Association (NASAA).

Oil wells and energy investments are among new financial scams targeted to older Americans. — Bill Ross/Corbis

Distressed real estate. So-called “investment pools” collect money to purchase and renovate distressed properties, then resell them at a profit. But these flips can be Ponzi flim-flams, using your money to pay off previous investors just enough to keep them off guard.

In one such case, 39 investors lost $2.3 million to a Florida man. His company never purchased properties as promised, but instead used the money to line his own pockets and make distributions to later investors. He was convicted in federal court.

Just like other securities, real estate shares must be registered with state regulators. Check with your state’s office to see if any would-be investment you’re eyeing has filed the proper paperwork.

Energy. Don’t believe promises of big returns from companies claiming access to untapped oil and gas deposits. Even legitimate energy investments “almost always bear a high degree of risk,” warns the NASAA. Energy investments may be a bad fit for retirement accounts, the group says, and “should be avoided by anyone who cannot afford to strike out when trying to strike it rich.”

Gold. As its value shined when stocks fell, two scam themes stood out: In one, a promoter says he’s raising capital to buy extraction equipment to reopen a long dormant mine. You’ll get a full refund on your investment plus interest and a stake in the mine.

In the other, the scammer claims to have coins or nuggets that can be stored or traded for you in special markets for high profits and returns. Either way, you take a beating. If you want to buy gold, ignore the promises made in unsolicited phone calls or late-night TV. Instead, speak to a trusted financial adviser about whether gold is right for you—keep in mind its price can and does crash.

Next: Are promissory notes often covers for Ponzi schemes?