Michael H Ziegelbaum

Insider

First SEC filing: Nov. 4, 2004 · Latest: Nov. 4, 2004

On this page

Insider at Companies where this person is a reporting insider.
Insider transactions Every share this person bought or sold, from Form 4 filings.
Derivatives Options and other derivative holdings reported by this person.
Initial holdings The stakes this person held when they first started reporting.

Insider at

MKTX selling Aug. 26, 2005

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 16 non-open-market transactions below last 12 months, based on the transactions shown below

Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted

16 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
Aug. 26, 2005	MKTX	M	10,000	$2.70	$27,000	20,000 Direct	+100.00%	Acquired	5892.2% (price as of 2026-08-20)
Aug. 26, 2005	MKTX	S	10,000	$11.00	$110,000	10,000 Direct	-50.00%	Disposed	1370.8% (price as of 2026-08-20)
Aug. 26, 2005	MKTX	M	10,000	—	—	36,294 Direct	-21.60%	Disposed	(price as of 2026-08-20)
Aug. 25, 2005	MKTX	M	5,000	$2.70	$13,500	15,000 Direct	+50.00%	Acquired	5892.2% (price as of 2026-08-20)
Aug. 25, 2005	MKTX	S	5,000	$11.00	$55,000	10,000 Direct	-33.33%	Disposed	1370.8% (price as of 2026-08-20)
Aug. 25, 2005	MKTX	M	5,000	—	—	46,294 Direct	-9.75%	Disposed	(price as of 2026-08-20)
July 29, 2005	MKTX	M	373	—	—	51,294 Direct	-0.72%	Disposed	(price as of 2026-08-20)
July 29, 2005	MKTX	S	373	$11.00	$4,103	10,000 Direct	-3.60%	Disposed	1370.8% (price as of 2026-08-20)
July 29, 2005	MKTX	M	373	$2.70	$1,007	10,373 Direct	+3.73%	Acquired	5892.2% (price as of 2026-08-20)
June 30, 2005	MKTX	M	7,000	$2.70	$18,900	17,000 Direct	+70.00%	Acquired	5892.2% (price as of 2026-08-20)
June 30, 2005	MKTX	S	1,500	$11.30	$16,950	15,500 Direct	-8.82%	Disposed	1331.8% (price as of 2026-08-20)
June 30, 2005	MKTX	S	1,000	$11.27	$11,270	14,500 Direct	-6.45%	Disposed	1335.6% (price as of 2026-08-20)
June 30, 2005	MKTX	S	200	$11.29	$2,258	14,300 Direct	-1.38%	Disposed	1333.0% (price as of 2026-08-20)
June 30, 2005	MKTX	S	1,300	$11.28	$14,664	13,000 Direct	-9.09%	Disposed	1334.3% (price as of 2026-08-20)
June 30, 2005	MKTX	S	200	$11.31	$2,262	12,800 Direct	-1.54%	Disposed	1330.5% (price as of 2026-08-20)
June 30, 2005	MKTX	S	200	$11.19	$2,238	12,600 Direct	-1.56%	Disposed	1345.8% (price as of 2026-08-20)
June 30, 2005	MKTX	S	900	$11.20	$10,080	11,700 Direct	-7.14%	Disposed	1344.6% (price as of 2026-08-20)
June 30, 2005	MKTX	S	200	$11.21	$2,242	11,500 Direct	-1.71%	Disposed	1343.3% (price as of 2026-08-20)
June 30, 2005	MKTX	S	1,200	$11.22	$13,464	10,300 Direct	-10.43%	Disposed	1342.0% (price as of 2026-08-20)
June 30, 2005	MKTX	S	100	$11.23	$1,123	10,200 Direct	-0.97%	Disposed	1340.7% (price as of 2026-08-20)
June 30, 2005	MKTX	S	200	$11.25	$2,250	10,000 Direct	-1.96%	Disposed	1338.1% (price as of 2026-08-20)
June 30, 2005	MKTX	M	7,000	—	—	10,000 Direct	-41.18%	Disposed	(price as of 2026-08-20)
June 14, 2005	MKTX	M	64,500	—	—	51,667 Direct	-55.52%	Disposed	(price as of 2026-08-20)
June 14, 2005	MKTX	S	9,100	$11.10	$101,010	10,000 Direct	-47.64%	Disposed	1357.6% (price as of 2026-08-20)
June 14, 2005	MKTX	S	55,400	$11.00	$609,400	19,100 Direct	-74.36%	Disposed	1370.8% (price as of 2026-08-20)
June 14, 2005	MKTX	M	64,500	$2.70	$174,150	74,500 Direct	+645.00%	Acquired	5892.2% (price as of 2026-08-20)
May 24, 2005	MKTX	M	300	—	—	116,167 Direct	-0.26%	Disposed	(price as of 2026-08-20)
May 24, 2005	MKTX	S	300	$11.00	$3,300	10,000 Direct	-2.91%	Disposed	1370.8% (price as of 2026-08-20)
May 24, 2005	MKTX	M	300	$2.70	$810	10,300 Direct	+3.00%	Acquired	5892.2% (price as of 2026-08-20)
May 23, 2005	MKTX	M	200	—	—	116,467 Direct	-0.17%	Disposed	(price as of 2026-08-20)
May 23, 2005	MKTX	S	200	$11.00	$2,200	10,000 Direct	-1.96%	Disposed	1370.8% (price as of 2026-08-20)
May 23, 2005	MKTX	M	200	$2.70	$540	10,200 Direct	+2.00%	Acquired	5892.2% (price as of 2026-08-20)
Jan. 6, 2005	MKTX	A	30,000	—	—	30,000 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 6, 2005	MKTX	A	10,000	—	—	10,000 Direct	—	Acquired	(price as of 2026-08-20)

P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding

Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.

Derivative holdings (Form 4 Table II)

Options, RSUs and convertible securities reported on Form 4 Table II.

Date	Ticker	Security	Underlying	Exercise price	Expiration	Shares	A/D
Aug. 26, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (10,000)	$2.70	Jan. 1, 2012	10,000	Disposed
Aug. 25, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (5,000)	$2.70	Jan. 1, 2012	5,000	Disposed
July 29, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (373)	$2.70	Jan. 1, 2012	373	Disposed
June 30, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (7,000)	$2.70	Dec. 30, 2012	7,000	Disposed
June 14, 2005	MKTX	Employye Stock Option (right to buy)	Common Stock (64,500)	$2.70	Jan. 1, 2012	64,500	Disposed
May 24, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (300)	$2.70	Jan. 1, 2012	300	Disposed
May 23, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (200)	$2.70	Jan. 1, 2012	200	Disposed
Jan. 6, 2005	MKTX	Employee Stock Option (right to buy)	Common Stock (30,000)	$15.60	Jan. 6, 2015	30,000	Acquired

Exercise/conversion price is blank when not applicable (e.g. RSUs).

Initial ownership (Form 3) 4 holdings

Securities held when first becoming an insider, per SEC Form 3.

Date	Ticker	Security	Shares	Ownership
Nov. 4, 2004	MKTX	Employee Stock Option (right to buy)→ Common Stock, par value $0.003 per share (133,334)	133,334	Direct
Nov. 4, 2004	MKTX	Employee Stock Option (right to buy)→ Common Stock, par value $0.003 per share (116,667)	116,667	Direct
Nov. 4, 2004	MKTX	Employee Stock Option (right to buy)→ Common Stock, par value $0.003 per share (83,334)	83,334	Direct
Nov. 4, 2004	MKTX	Employee Stock Option (right to buy)→ Common Stock, par value $0.003 per share (50,000)	50,000	Direct