CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012
Cash flows from operating activities
Net (loss) income	$ (40,198)	[1]	$ 36,397	[1]
(Loss) Income from discontinued operations, net of tax	(28,901)	[1]	491	[1]
(Loss) income from continuing operations, net of tax	(11,297)	[1]	35,906	[1]
Adjustments to reconcile (loss) income from continuing operations, net of tax to net cash provided by (used in) operating activities
Stock-based compensation	47,666		22,503
Depreciation and amortization	19,632	[1]	23,031	[1]
Writedown of assets	17,787	[1]	0	[1]
Debt discount accretion and other debt related expenses	9,545		8,646
Unrealized and realized gains on investments, net	(5,485)		(10,006)
Deferred rent	(593)		(229)
Operating activities from discontinued operations	57,831		(5,857)
(Increase) decrease in operating assets
Cash and securities segregated under federal and other regulations	(36,054)		(58,740)
Financial instruments owned, at fair value	(1,372,201)		(1,099,829)
Securities borrowed	(150,261)		(413,134)
Receivable from brokers, dealers and clearing organizations	(498,169)		96,222
Income taxes receivable	146,090		(19,895)
Other assets	(3,922)		(13,470)
Increase (decrease) in operating liabilities
Financial instruments sold, not yet purchased, at fair value	67,781		(37,107)
Securities loaned	122,809		541,170
Financial instruments sold under agreements to repurchase	190,000		25,000
Other secured financings	(50,418)		37,035
Liability to GNMA trusts, at fair value	1,281,599		1,006,696
Payable to brokers and dealers and clearing organizations	257,189		(59,009)
Payable to customers	139,242		(63,988)
Accrued compensation expense	(30,183)		(65,829)
Accrued expenses and other liabilities	46,446		3,706
Net cash provided by (used in) operating activities	245,034		(47,178)
Cash flows from investing activities
Proceeds and distributions from investments	4,991		3,309
Purchases of investments	(1,439)		(9,747)
Purchases of fixed assets and leasehold improvements	(11,132)		(13,951)
Purchase of intangible asset	0		(50)
Purchase of business, net of cash acquired	0		(3,268)
Investing activities from discontinued operations	(502)		(1,260)
Net cash used in investing activities	(8,082)		(24,967)
Cash flows from financing activities
Repayment of debt	(100,000)		0
Stock options exercised	0		1,076
Income tax (benefit) provision related to stock-based compensation	(12,103)		170
Cost of common stock repurchased	(11,566)		(32,024)
Payment of dividend related to convertible preferred shares	(1,217)		0
Net cash used in financing activities	(124,886)		(30,778)
Effect of exchange rate changes on cash and cash equivalents	(3,674)		88
Increase (decrease) in cash and cash equivalents	108,392		(102,835)
Cash and cash equivalents at beginning of period	413,926		467,633
Cash and cash equivalents at end of period	522,318		364,798
Supplemental disclosure of cash flow information:
Cash paid for interest	17,018		32,318
Cash paid for income taxes	$ 3,380		$ 44,166

[1] See Explanatory Note - All financial information is of Knight Capital Group, Inc. As of July 1, 2013, Knight Capital Group, Inc., became a wholly-owned subsidiary of KCG