Commitments and Contingent Liabilities (Tables)

6 Months Ended

Jun. 30, 2013

Commitments and Contingencies Disclosure [Abstract]

Schedule of Lease and Contract Obligations

The Company leases certain computer and other equipment under noncancelable operating leases. As of June 30, 2013, future minimum rental commitments under all noncancelable office, computer and equipment leases (“Gross Lease Obligations”), and Sublease Income were as follows (in thousands):

Fair Value of Asset or Liability on Futures Contracts Activity

The following tables summarize the Company’s futures contract activity (in thousands):

Futures Contracts	Statements of Financial Condition Location	Fair Value of (liability)
		June 30, 2013			December 31, 2012
Notional Value	Not Applicable	$	(205,761	)	$	(180,512	)
Fair Value	Payable to brokers, dealers and clearing organizations	$	(836	)	$	(1,923	)

Loss recognized on future contracts activity

		Gain Recognized
		For the three months   ended June 30,
Futures Contracts	Statements of Operations Location	2013		2012
Unrealized gain	Net trading revenue	$	4,181	$	16,266

		Gain Recognized
		For the six months   ended June 30,
Futures Contracts	Statements of Operations Location	2013		2012
Unrealized gain	Net trading revenue	$	6,449	$	11,426