Which factor is NOT one of the five determinants of a credit score?

The factor that is not one of the five determinants of a credit score is the investment portfolio. Credit scores are primarily influenced by factors directly related to credit usage and repayment patterns. These factors include payment history, length of credit history, the amount of debt owed, types of credit in use, and new credit inquiries.

An investment portfolio, which consists of financial assets such as stocks, bonds, and other investment vehicles, does not have a direct impact on an individual's creditworthiness or their ability to manage credit. Therefore, it is not considered a determinant in computing a credit score, making it the correct answer in this context. Understanding the five proper determinants is essential for anyone looking to improve or understand their credit score better.