They made a gamble that if they needed to redeem them early that they would be able to do so without much penalty and that they wouldn't need to redeem too much if any (new deposits would cover old assets).

They lost on multiple fronts, interest rates rose so much that it became a huge loss to sell these bonds, the tech market slowed down meaning that fewer companies were getting infusions of cash and more of them were burning through their cash piles and the final death knell was that word of all this got out and it started a bank run.