During the week that the bankers behind Facebook's initial public offering issued their first ratings on the company, its shares fell nearly 6 percent.

The stock ended trading Friday at $31.09, down 27 cents for the day. For the week, it lost almost $2, or 5.9 percent, compared with last Friday's closing price of $33.05.

The 40-day quiet period for analysts who work for the banks that underwrote Facebook Inc.'s IPO ended this week, meaning they finally could issue ratings and opinions on the stock.

In a flood of reports on Wednesday, they mostly rated it "neutral" or "buy." Morgan Stanley, the lead bank for the IPO, set a target price of $38.

That's the very same price it initially sold for - and has failed to match since.