ICE's fourth quarter 2025 earnings release and presentation can be found in the investor section of ice.com. You will find a reconciliation to the equivalent GAAP term in the earnings materials. When used on this call, net revenue refers to revenue net of transaction-based expenses. Throughout this presentation, unless otherwise indicated, references to revenue growth are on a constant currency basis.
Please see the explanatory notes on the second page of the earnings supplement for additional details regarding the definition of certain items. I'll begin on slide 4 with our exceptional full year 2025 results, which demonstrate the strength of our diversified business model and the consistency of our execution. We delivered record adjusted earnings per share of $6.95, a 14% increase year-over-year, marking the best performance in our company's history. These results drove record adjusted operating income of $6 billion, up 9% year-over-year, demonstrating the quality and scalability of our business model.
Turning to capital allocation, our record operating performance generated $4.2 billion of, in adjusted free cash flow, which we deployed strategically to enhance shareholder value. This balanced approach reflects our confidence in both our core operations and our ability to capitalize on future growth opportunities. Fourth quarter adjusted earnings per share totaled $1.71, up 13% versus the prior year. Fourth quarter net revenues of $2.5 billion increased 7% year-over-year, with transaction revenues growing 8%, and recurring revenues advancing 6%.