Can a corporation stop a fundamental change if too many shareholders exercise dissent rights?

Exercising dissent rights under the OBCA does not block or veto the underlying fundamental change itself — if the required shareholder vote, often a special resolution requiring a higher approval threshold than an ordinary matter, passes, the transaction can generally proceed even if a significant number of shareholders formally dissent. Dissent rights give an individual shareholder an exit through a fair-value buyout, not a collective veto power.

That said, a large number of dissenting shareholders can create a serious practical problem for the corporation completing the transaction: it may need to pay out fair value to every dissenting shareholder, potentially requiring a substantial amount of cash it had not planned to spend, which in an extreme case could affect the corporation's ability to complete the transaction as structured. Some transaction agreements for larger deals include a dissent-threshold condition, letting the acquiring or surviving corporation walk away if too many shareholders dissent and the payout obligation becomes too large, but that comes from the specific transaction agreement, not from the OBCA's dissent provisions themselves. Dissent is an individual remedy with potential collective financial consequences, not a mechanism shareholders can use together to block the vote's outcome.