Your Investment Portfolio Cannot Be Added to Your Credit Report

A credit report only includes information about matters pertaining to credit and debt. It does not include information about investments, income or any other asset.  So we are credit report will not include information about your fixed deposits, mutual funds, 401k account etc.
Even though a lender might require you to provide proof of income in order to determine the debt to income ratio this information is not reported to the credit bureau.  A lender very often asks for a statement of income specially in cases where a large amount of loan is under consideration such as a mortgage loan. This helps them to determine your ability to manage the liability of the new debt.
The loans that you take for your self from your 401k account are not part of your credit report either.  These loans are considered to be loans to yourself from your own savings.
Also it should be noted that it is almost impossible for any individual to try and report information about their own activities to the credit bureau.  Being able to report to a credit bureau will involve joining their programme and being able to meet their guidelines regarding data management, operation and dispute handling.  This kind of arrangement requires a lot in terms of money and infrastructure.  So it will be impossible for individuals to report information to the credit bureaus.