Second Sight Medical Products on Monday closed its $27.9 million private stock placement, selling 4.7 million shares at $6 each, a move first announced last Wednesday.

Net proceeds will be used as working capital, the Sylmar visual prosthetics company said in a statement. ThinkEquity, a Fordham Financial Management Inc. division based in San Francisco, acted as sole placement agent for the offering.

Shares of Second Sight plummeted more than 25 percent the day of the announcement. On Monday shares of Second Sight (EYES) closed down 90 cents, or nearly 10 percent, to $8.21 on the Nasdaq.

Some commenters on Yahoo Finance’s message board for Second Sight said the stock drop was due to dilution caused by an increased number of shares. Others said they weren’t concerned by the drop, adding the “big play investors are still in on this,” and that they will follow their lead and hold shares.