Shares of Zafgen fell 35%, to $22.15, on Monday after the company suddenly cancelled both a "road show" investor presentation arranged by RBC Capital, and a Wednesday investor dinner organized by Maxim Group. Those shares have yo-yoed since then, plunging another 29% to $15.75 on Tuesday, climbing back 33.5% to $21.02 yesterday, then falling again 29% this morning, to $14.85 as of 9 a.m. ET in after-hours trading.