Hi jnycat,
The way I understand it is very simple, and is this.
There is no guaranteed share price(s).
For every 20 shares of ECU you hold, you will receive one AUM share, at the pre-determined date when the merger officially receives approval to go forward.
From that date on, whatever price AUM trades at, will be the unit value of your "new" quantity of shares.
Suggest ECU and AUM will probably trade "in step" until then.
If merger does not get approval, nothing will change.
If someone has a different interpretation of "the plan" would appreciate a detailed explanation.
Good Luck to all!