The Top 10 lies told on Wall Street

We've seen a lot of fibbers outed recently. And when it's a trusted newsman like Brian Williams or a military veteran like Secretary of Veterans Affairs Robert McDonald, we feel betrayed to learn that they've been lying to us. But if I told you someone on Wall Street was caught lying, you'd probably shrug it off and say, "That's what we call Tuesday."

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There's a dichotomy in which the high finance world (and politics and Hollywood, for that matter) live. It's based on two basic premises: First, everyone is a liar until proven otherwise; and second, a quote from Ernest Hemingway, "the best way to find out if you can trust somebody is to trust them."

It's not easy. If you trust everyone on Wall Street you won't be successful and if you trust no one on Wall Street you won't be successful either. There has to be a balance. Part of the trick is figuring out who — and what — to believe.

Here are the 10 most common little white lies told on Wall Street:

1."I have a business dinner tonight." This is the go-to get-out-of-jail-free card. It's hard to disprove. A business dinner is the lifeline of a salesman, which makes it difficult for a wife, husband, co-worker or client to call bullshit.

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2. "My client brought his entire trading desk to dinner." If the bill is so high you think the finance department is going to freak out, you start adding names — on the client side. One night, I was allegedly at three different business dinners in the city all at the same time. I was on my couch, but my name looked good on the expense report.

3. "You got one of our best allocations." Whenever a hot IPO deal is priced/ all of the salesmen have to call their clients to give them their allocation. And no client is ever happy with the amount of stock they got. But your broker tries to coddle their clients with lies of encouragement.

4. "We spoke to the company." While those words might be true, anything that follows it is most likely a lie because if, in fact, that person actually did speak with the company, she wouldn't divulge such information.

5. "The big boss is in town." This is a desperate move to get the client to send his order in right now "because the big boss is watching." He just wants business and couldn't think of anything else. Why should you care about HIS boss?

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6. "I have a seller of 250k XYZ and it cleans him up on 3.8 million shares." This is one of the oldest tricks in the book. It essentially means that a broker is trying to get you to buy a block of stock with the promise that this is the end of this sell order and the stock will likely go up right after this. Unless you're related to the person saying this or you have incriminating photos of him, DO NOT believe it. Either he's lying – or his client is.

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7. "I'm a natural." No, this doesn't mean "I'm a natural at trading." It means that I have an actual order that is the opposite of your trade (e.g., I have a buy order for what you're selling), so I'm a natural fit and we can get this trade done quickly. Brokers will do anything to get an order and order flow is one of the easiest ways to do it. They're trying to smoke out the real buyers and sellers with false liquidity. It happens all day every day.

8. "There's no more cocaine left." There's always a secret stash — it's just not for you. The only time that statement is believable is when it's 6 a.m. and the person is licking a glass coffee table; otherwise, it's a bold-faced lie.

9. "I'm sorry, but he's off the desk this morning. He had a breakfast meeting." This is the co-worker's line straight from the manual of I HAVE NO IDEA WHERE HE IS THIS MORNING. The last thing you want to do is blow up a co-worker's lie. So regardless of where he really is, he's always in a breakfast meeting when he's unaccounted for.

10. "I'm not lying." Ding! First sign a person is lying.

Commentary by Turney Duff, a former trader at the hedge fund Galleon Group. Duff chronicled the spectacular rise and fall of his career on Wall Street in the book, "The Buy Side," and is currently working on his second book, a Wall Street novel. He is also featured on the CNBC show, "The Filthy Rich Guide." Follow him on Twitter @turneyduff.

Can't get enough money, greed and lies? Tune in to CNBC's "American Greed" Thursdays at 10pm ET/PT. Tonight, an all-new episode about a suave Miami "tycoon" who scammed big money from some big names in the name of helping the poor. (Click here for a sneak peek or watch the clip below.)