http://ftalphaville.ft.com/blog/2007/08/15/6583/how-to-deal-with-the-what-is-it-worth-problem/ The upheavals in debt markets because of the subprime-mortgage shakeout have left some investment funds wondering how to value their holdings, notes the Wall Street Journalâs Heard on the Street column. Last week, Franceâs BNP Paribas said it would stop the flow of money into and out of three of its investment funds because it couldnât âfairlyâ value securities in the funds. That, the bank said, made it impossible to come up with a net asset value for the funds that would allow investors to get in or out, notes the column. When the bank, for example, recently tried to sell about $60m of bonds backed by US mortgages, it couldnât find any buyers. Among the brokers it called, âsome of them werenât even answering the phone,â Alain Papiasse, head of BNPâs asset-management and services division, told the Journal.