Incorrectly regarded as goofs: After Seth and Chris have their argument in the stairwell right off of the boiler room, Seth goes down at least one flight of stairs on his way out. In the next scene he passes Abby in the receptionist area that is on the same floor as the boiler room - because he's been bumped upstairs to nicer offices.
Continuity: Also in the last scene, Seth's car is beside a black VW Passat and the red Diablo is beside the Passat. When he pulls out (now perpendicularly parked and seen from above) the Passat is gone.
Incorrectly regarded as goofs: When Seth's father calls him to say that he would go in with him with the IPO scam he states first that "I'll make sure you won't get caught" and then "I have a friend..." While the FBI playback is different, since this wasn't court testimony, they may have been using an altered tape.
Errors in geography: When Seth is avoiding talking to Harry Reynard, Seth's secretary has a cup from Seattle's Best Coffee. While this brand is not exclusively sold in Seattle, they had no locations in New York or New Jersey at the time of the movie.
Errors in geography: Seth mentions that the brokers act like they are taking the 6 train to Fulton Street when in fact you take the 4/5 to Fulton Street. The 6 only goes to City Hall/Brooklyn Bridge.
Continuity: When Michael is talking to the room full of brokers to tell them about the party, his tie pin is alternately closed/open between shots.
Continuity: Seth invites his father to a diner for lunch and arranges the napkins on the table. After his father sits down, the napkins are back in their original positions.
Errors in geography: When Seth is driving on the Long Island Expressway he says he goes to his interview off exit 53. In the next frame you see Seth driving on Northern Blvd. which is exit 32. Further in this scene we see Seth driving on Northern Blvd. east but then cuts to a scene where he is traveling west on Northern Blvd. which would make him driving the total opposite way of where he wanted to go.
Errors made by characters (possibly deliberate errors by the filmmakers): Greg is introduced as "Greg Weinstein" by Michael, yet moments later the leader board names him as "Greg Feinstein".
Continuity: Ben Affleck refers to his Ferrari 355 as a "Cabriolet". Ferrari convertibles are called "Spiders".
Factual errors: When the FBI arrests Seth, they tell him to go to work the next day and copy his C Drive onto a floppy. This would be impossible as a floppy disc only holds 1.5 megabytes and his Hard Drive would hold at least 20 or more Gigabytes.