The April options cycle expires on Friday, April 21. Not including today, this leaves 3 days of trading before expiry.
KCG Holdings (NYSE: KCG) is hovering around US$17.50 and their April 18 call options have a substantial bid of 16 cents, which puts them at an implied volatility of about 48%. Their historical volatility has been much less than this (typical options have been trading at around 20-25%, depending).
This is somewhat unusual, and probably instigated by the previous unsolicited buyout proposal at US$18-20/share prompted by Virtu (Nasdaq: VIRT) last month. Will there be a more solid proposal that will be made public soon?