World’s stock markets ‘knew’ 9/11 was coming

Geoff Ward
10 min readSep 9, 2021

The day before 9/11, financial markets worldwide suddenly slumped — had they somehow sensed the imminent catastrophe? Was it ‘the most important crime of insider trading ever committed’?

The world’s stock markets ‘knew’ 9/11 was coming, says a global market researcher on the eve of the 20th anniversary of the disaster.

For 18 months prior to 9/11, the world’s financial markets were in continuous decline and then, on September 10, 2001, their values suddenly plummeted, recalls the Dutch global market analyst Herma Koornwinder.

As proof, she produced a dramatic sequence of graphs covering the downward trends of the world’s stock exchanges in 2000–2001. The day before the attacks on the World Trade Center and the Pentagon, markets worldwide plunged. Significantly, shares of airlines and insurance companies were the most affected.

‘Share prices are the result of human behaviour and that creates patterns that show up in graphs,’ she said. ‘It was as if the markets knew! My research shows that something strange was happening.’

Herma has sought to explode the ‘myth’ that stock markets collapsed because of 9/11 when, in fact, they cascaded down before the event. Afterwards, they went up.

‘It has been put into the collective mind that the markets crashed because of 9/11,’ she said. ‘It is not the case. There was a shock-wave immediately afterwards but within a few days the markets climbed again.’

Herma compiled two series of graphs covering 19 indices around the world: one reveals steady decline from March 24, 2000, until the sudden drop on September 10, 2001, and the other shows a marked increase soon after September 11, 2001.

Indices covered were Brazil Sao Paolo, Budapest, Buenos Aires, China Hang Seng, Europe Eurostoxx 50, France CAC 40, Germany DAX, Helsinki, Istanbul, Madrid, Milan, Netherlands AEX, Switzerland MSI, Tokyo Nikkei, UK FTSE 100, USA Dow-Jones Industry, USA Nasdaq Composite, USA S&P and World MSCI. These were a sample from 60 indices which Herma researched, all of which showed a similar pattern.



Geoff Ward

Writer, journalist, book editor, poet, musician and tutor in literature and creative writing (MA and BA Hons degrees in English literature).