He wanted the shares cheap and to make sure of this, he stopped paying Scarlett's school fees, prompting Carrie to confront the Kings when she learned of this, having told Scarlett to stay in the car.
He wanted the shares cheap and to make sure this happened, he cut off all payments to Carrie, one of which was Scarlett's school fees. The school told Carrie the fees had not been paid and suspended Scarlett so Carrie confronted Matthew, having told Scarlett to stay in the car.