The new public New York Stock Exchange may pose a thorny problem for investors that happen to hold mutual funds that trade on the NYSE. Mercer Bullard, the founder and head of Fund Democracy, told MarketWatch, that it could be "a conflict of interest" if a NYSE investors holds 5% or more of the company stock and is also a broker of mutual funds. 

"The question is whether it's going to be subject to the rule for affiliated brokers or whether it would be just prohibited outright as a joint transaction," said Bullard. If it's the latter, the Securities and Exchange Commission would first have to approve the transaction. One such company facing that possible issue is Goldman Sachs, which offers mutual funds and reportedly holds more than a 15% stake in Archipelago stock (at least as of late last year). A spokesman for GS told MarketWatch, however, that the firm examined the situation and said, "we believe this won't be an issue."