The 7 Biggest Conspiracy Theories about 9/11 still around today

On the 14th anniversary of the Sept. 11 attacks, it seems many factors relating to the events of that tragic day persist as a mystery.


Most 9/11 conspiracy theories have more or less been debunked, but they live on, sparking skepticism in people’s minds as to who or what was really behind the attacks.

Below is a list of the seven most popular conspiracy theories surrounding the Sept. 11 attacks. Has the government intentionally kept us in the dark, or has it come clean with everything it knows?

1. Trading insiders had advance knowledge of 9/11


Immediately prior to 9/11, an unusually high number of put options were placed on stocks of the two carriers used in the attacks — United Airlines and American Airlines. Put options are option contracts in which the buyer has the right to buy a specific quantity of a stock at a set price within a fixed period of time.

Conspiracy theorists believe trading insiders had prior knowledge of the 9/11 attacks, and made financial decisions accordingly.

The 9/11 Commission report ultimately discredited this theory, concluding no evidence was found that suggested anyone with advance knowledge of the attacks profited from these stock purchases.

2. Air defense was told to stand down


US air defense didn’t respond in time to news that hijacked airplanes were nearing the World Trade Centers. Conspiracy theorists posit this is because the North American Aerospace Defense Command either notified fighter jets of the threat too late or because it issued a stand-down order. This theory aligns with the belief that the US government was complicit in the attacks because it knew about them in advance but did nothing to stop them.This hypothesis doesn’t hold up because only 14 fighters were on duty at the time of the attacks, and no alarm or computer system was in place to automatically notify NORAD of the missing carriers. In the decade prior to 9/11, NORAD had only intercepted one plane — a chartered Learjet 35 — and it took command one hour and 19 minutes to reach it.

3. A plane didn’t fly into the Pentagon


“How does a plane 125 feet wide and 155 feet long fit into a hole which is only 16 feet across?” asks. Conspiracy theorists have widely circulated the theory that a Boeing 757 could not have made the hole. French author Thierry Meyssan believes it was actually a satellite-guided missile that struck the Pentagon as part of an elaborate military plot pitting US military personnel against other military personnel.

While we may expect a plane crashing into a building to produce a cartoon-like outline, that’s not generally what happens in such scenarios, notes Mete Sozen, an American Society of Civil Engineers member, who is also a professor of structural engineering. “If you expected the entire wing to cut into the building, it didn’t happen,” he told Popular Mechanics.

4. United Airlines Flight 93


The only plane on Sept. 11, 2001 to not reach its target, Flight 93 is suspected by conspiracy theorists of having been shot down by a US fighter jet. When planes crash, they usually leave a small debris field. In this instance, debris was discovered miles away from the location of most of the wreckage. The crash resulted in damage that would indicate the airliner was struck by a heat-seeking missile, according to

Six eyewitnesses claim to have seen a small white jet flying at low altitude not long after Flight 93 crashed, but the FBI says what they actually saw was a private jet, which was asked to descend to 5,000 feet to seek out the crash site.

5. Bombs collapsed the towers, not planes

Many conspiracy theorists, including engineering and architecture experts from acclaimed universities, see striking similarities between how the Twin Towers collapsed and how buildings collapse when they undergo controlled demolition. They suggest the impact caused by the planes crashing into the New York city landmarks couldn’t have possibly caused their rapid and complete collapse on its own; explosives planted at the bottom of the building helped.

If there were indeed explosives capable of collapsing skyscrapers already in the building at the time of the attacks, would they not have been detected during routine maintenance?

6. The hijackers are still alive


Immediately following the attacks, the BBC published the identities of the individuals assumed to have been the hijackers. Of the people named, some were subsequently found to be alive, a fact taken by conspiracy theorists to be proof that elements of the hijacking were faked.

The names were common Arabic and Islamic names, and both The New York Times and BBC later confirmed that the confusion surrounding them was a case of mistaken identity.

7. Several foreign powers helped to orchestrate the attacks


It has been suggested by conspiracy theorists that both Pakistan and Saudi Arabia financed the attacks. It’s also alleged that Israel’s foreign intelligence agency had knowledge of the attacks prior to 9/11.This theory stems from the 28 pages redacted from the 9/11 Commission report. Unless these pages are made public, it’s unlikely we’ll know whether there is any truth to this claim.