2001 will remain in collective memory as the year terrorism struck the financial heart of the United States. The attack on the Twin Towers on 11 September was not merely a human and geopolitical tragedy: it had immediate and far-reaching repercussions on global markets. The New York Stock Exchange remained closed for four days, and on reopening suffered one of the most violent collapses in recent history. Yet alongside the post-attack reaction, another story — darker and more controversial — is woven into those days: that of the financial anomalies recorded in the days and hours preceding the attacks.

Immediate market reaction: the financial trauma

On the reopening of the NYSE on 17 September 2001:

  • Dow Jones: –684 points in a single session (–7.1%), the worst single-day fall ever recorded up to that point.
  • Nasdaq: –6.8%, with technology stocks in free fall.
  • Sectors hit hardest: aviation, tourism, insurance.
  • “Safe haven” sectors: defence, security, intelligence.

In the days that followed, the Federal Reserve cut rates by 50 basis points and injected massive amounts of liquidity to avert a systemic collapse.

Anomalies before the attack: data, volumes and suspicious timing

From as early as 6 September 2001, certain analysts noted volumes on specific securities — directly linked to the events — that were entirely out of scale:

  • United Airlines (UAL): on 6 September, three days before the attack, the volume of put options was four times higher than the monthly average.
  • American Airlines (AMR): on 10 September, the eve of the attack, put volumes were recorded at twenty times the norm.
  • Morgan Stanley: one of the largest tenants of the World Trade Centre, saw an anomalous increase in bearish options.
  • Marsh & McLennan: the insurance company, also with offices in the Towers, recorded suspicious movements.

According to a report by the University of Illinois and the Chicago Board Options Exchange (CBOE), such volumes were statistically improbable under normal conditions and were suggestive of insider information.

The official investigations and their contested outcome

The SEC (Securities and Exchange Commission) launched an investigation, joined by the FBI. The official report concluded that:

“No conclusive evidence was found of insider trading directly linked to Al Qaeda or those responsible for the attacks.”

However, not all investigators agreed.

The 9/11 Commission Report minimised the significance of these transactions, explaining them away as coincidences or hedging operations.

Many independent researchers contested this account, considering the investigation to have been conducted far too narrowly, without pursuing leads that could have connected international financial intermediaries to intelligence networks.

Conspiracy theories: who could have known?

The central hypothesis advanced by conspiracy theorists is that certain financial operators received privileged information and placed bets on the collapse of specific securities. The principal theories fall into three strands:

  1. Terrorist networks with support within the financial system
    • Several reports from the Bundesbank and German intelligence suggested that financial contacts of Al Qaeda may have operated through European and Swiss intermediaries.
    • Transactions were said to have passed through banks such as AB Brown, whose former executive director, A.B. “Buzzy” Krongard, subsequently became Executive Director of the CIA.
  2. Indirect involvement of Western intelligence services
    • According to Michael C. Ruppert, a former Los Angeles police investigator and author of Crossing the Rubicon, the suspicious operations were allegedly conducted by individuals connected to US and allied intelligence networks, using insider knowledge not to prevent the attack, but to profit from it.
    • These claims fit within the “false flag” narrative: the idea that the attack was allowed to happen or was orchestrated to justify wars in Afghanistan and Iraq.
  3. Opaque finance and offshore circuits
    • Many put option transactions were linked to accounts held at offshore branches, protected by banking secrecy.
    • According to studies from the University of Zurich, full tracing of the ultimate beneficiaries proved “impossible owing to a lack of international cooperation”.

The unresolved question: coincidence or financial foreknowledge?

More than twenty years on, there is no “smoking gun” directly linking the suspicious movements to the perpetrators of the attacks. Nevertheless:

  • The anomalous volumes remain an objective, documented fact.
  • The hasty closure of the investigations and the lack of transparency continue to fuel suspicion.
  • The timing of the transactions is difficult to explain without positing advance knowledge of the events.

Conclusion: 9/11 as a watershed moment for crisis finance

11 September 2001 marked not only the beginning of the “War on Terror” but also a paradigm shift in the markets: sudden volatility as opportunity, speculation on catastrophic events as strategy, and an ever-tighter interweaving of finance, intelligence and geopolitics.

In that shadow — where statistics meet affairs of state — one question remains open:

did someone foresee the financial collapse of 11 September… or did someone plan it for profit?