Markets generally over-react to geopolitical disasters and events.
This might not be one of those times. There’s a rumor that Ukraine rebels claimed responsibility for shooting down a Ukrainian military transport plane at around the same time as the crash. It seems highly likely to me that Ukranian rebels made a mistake and this terrible tragedy is the result.
Rumors that separatists took responsibility but we warn that other (military) planes were shot down earlier
What happens now?
Russian will now come under extreme pressure to break the Ukraine separatist rebellion. So will the Ukranian government. In any case, I can’t see the separatist movement surviving this. Public sentiment in Russia and elsewhere will turn sharply against them.
Ultimately that will be good news. The first signs will have to come from the Kremlin and they must be extremely quick to condemn this attack and turn face on the rebels. If they continue to support the rebels, anger will shift toward Russia and that could mean harsh sanctions or worse.
An even worse risk is that some outside armed force uses this as a reason to get involved.
Bottom line: Watch for the response from Russia.