Most common types of financial scams an individual investor should beware of?
Affinity fraud. You see, Madoff really didn't have to sell himself, people recommended him to their friends.  In a similar way, it's easy once a scammer reels in one sucker to keep him on the hook long enough to get 10 friends to invest as well.  I've written about Mortgage Acceleration scams, and the common thread is that they are first sold to friends, relatives, neighbors. People tell their fellow church goer about it and pretty soon people's belief just takes over as they want it to work.  Edit - the scam I referenced above was the "Money Merge Account" and its reincarnated "Wealth Unlimited." It claimed to use sophisticated software to enable one to pay their mortgage in less than half the time while not changing their budget. The sellers of the product weren't able to explain how it was supposed to work, since it was nonsense anyway. You were supposed to be able to borrow against a HELOC at a rate higher than your mortgage, yet come out ahead, enough to cut the time in half or less. The link I posted above leads to a spreadsheet I wrote in a weekend, which was better at the math than their software and free. It also linked to 66 pages of accumulated writing I did over a number of months starting in 2008. In the end, I never saw any prosecution over this scam, I suppose people were too embarrassed once they realized they wasted $3500.  How can I get scammed buying S&P ETFs through Schwab? Easy, I can't.