Competition increases risk taking behaviour, so I suppose the smell of risk would be an unstable scent.
And adrenalin would heighten the senses and the sense of smell.
When I think of instability, I think of a drag race — losing control very quickly. Recalling reckless driving as a teenager in Sydney ’burbs, like West Ryde where there was a drag strip (I think they eventually installed speed humps). At high speeds minor things can have major consequences.
This would be a scent to stay calm in a risky situation.
burning rubber, salt plains, lpg gas, with the calm of red wine, frangipani and joints