Facebook is being accused of advising some - but not all - underwriters to cut their forecasts for the company in the run-up to its IPO.
According to Reuters, feedback from the investor roadshow made it clear that mobile advertising revenue might be disappointing, and the company decided to warn analysts at some banks which were underwriting the deal.
While underwriters themselves are banned from issuing research on IPOs they're involved in, there's no such restriction on the bank analysts, who are allowed to pass information on to their clients.
It's very, very unusual for a forecast to be revised in this way so close to an IPO.
While it's not known which analysts might have been briefed, lead underwriter Morgan Stanley reduced its revenue forecasts at just this time, and warned some of its institutional investors. The company insists it's complied with all applicable regulations.
The Wall Street Journal says Goldman Sachs gave a similar warning at the same time.
The news, if true, means that while many large investors were warned of the revised outlook, smaller investors weren't. And with Facebook stock now trading at $31, after launching at $38, many may believe they've been misled.
Both the Securities and Exchange Commission and the Financial Industry Regulatory Authority are believed to be investigating.