KEY POINTS
  • Herbalife shares dropped Monday after the company lowered its sales outlook for the second quarter.
  • Hedge fund manager and long-time critic of the supplement company responded to the move by Herbalife.
  • Ackman wants Herbalife to explain recent insider sales before this guidance update and also wants clarification on reports of recent executive departures.

After Herbalife lowered its sales guidance Monday, blaming disruptions caused by new FTC guidelines, manager and long-time company critic Bill Ackman seized on the announcement with a statement of his own.

"On May 4th Herbalife raised guidance driving the stock to new highs. Insiders including [CEO Michael] Johnson sold their stock and options. Fewer than three weeks after the stock sales, the company is now lowering guidance, somehow claiming that it is surprised by reduced volumes the first month the FTC settlement takes effect," the hedge-fund manager said in a statement emailed to CNBC.