The dangers of "Agreed value" insurance and short selling.
 

I was flying for a small company in the US last year and because the aircraft was suffering from rather a large number of defects and the owner of the company was a rather interesting chap who had, "Lost" an aircraft before under rather unusual circumstances, I decided to take a long hard look at the insurance policy.
It was an agreed value hull and 3rd party policy from a company I had never heard of in the US. A few enquiries behind the scenes revealed that the company had informed a potential customer that the aircraft was worth 20 million usd! I suspect that figure was based on a new aircraft of a similar type (A rare one) being sold to a US company for that sum, although I'm sure the insurance broker would not have issued a policy for that amount as the aircraft was not new, but they might have issued a policy for 10 million usd.
A nice little earner in the event of a crash, because in my opinion the aircraft was in a poor condition and only worth perhaps 2 to 3 million usd max.

Coffin ship insurance policies are not just a thing of the past, but alive and well it seems!

All agreed value insurance policies should be published with the figures visible on the insurance certificate.

Not sure if it's possible to short sell a cargo airlines stock listed on an EU market, but it sure is overseas.
When something bad happens as regards a terrorist attack or even an aircraft disappearing, there is often a profit motive involved and I can almost guarantee you, that when an airliner is lost, if the major stock holders are private folks, they will have set up a system that will dump that stock even before the news hits the press.

Allowing the short selling or even flash trading of any airline stock is nuts!

If the aircraft is over insured that's bad for the insurance company. They should be adjusting the value of the aircraft depending on the condition. If what you say is true, the underwriter is not doing a very good job of underwriting.