Spero sags after $77M listing

Spero Therapeutics Inc. (NASDAQ:SPRO) sank $2.50 (18%) to $11.50 on Thursday after raising $77 million through the sale of 5.5 million shares at $14 in an IPO underwritten by BofA Merrill Lynch, Cowen, Stifel and Oppenheimer. The price, which was at the bottom end of Spero's proposed range, valued the company at $194.6 million.

Last month, Spero hoped to sell 5 million shares at $14-$16. At the $15 midpoint, a sale of that many shares would have raised $75 million and valued Spero at $201 million...