Mechanism in a stock-for-stock deal that limits how much the deal value can move between announcement and closing as the acquirer's share price fluctuates. Fixed Exchange Ratio: target receives a fixed number of acquirer shares per target share — target's value moves 1-for-1 with the acquirer stock. Fixed Value with Collar: exchange ratio floats within a range to hold dollar consideration constant within a band; below the floor the ratio caps (value drops) and above the ceiling the ratio floors (value rises). Protects the target against moderate declines in the acquirer's stock while protecting the acquirer from issuing too many shares.