Introduction

This page provides a comprehensive analysis of the known insider trading history of David C Dvorak. Insiders are officers, directors, or significant investors in a company. It is illegal for insiders to make trades in their companies based on specific, non-public information. This does not mean it is illegal for them to make any trades in their own companies. However, they must report all trades to the SEC via a Form 4. Despite these restrictions, academic research suggests that insiders - in general - tend to outperform the market in their own companies.

Average Trade Profitability

The average trade profitability is the average return of all the open market purchases made by the insider in the last three years. To calculate this, we examine every open-market, unplanned purchase made by the insider, excluding all trades that were marked as part of a 10b5-1 trading plan. We then calculate the average performance of those trades over 3, 6, and 12 months, averaging each of those durations to generate a final performance metric for each trade. Finally, we average all of the performance metrics to calculate a performance metric for the insider. This list only includes insiders that have made at least three trades in the last two years.

If this insiders trade profitability is "N/A", then the insider either has not made any open-market purchases in the last three years, or the trades they’ve made are too recent to calculate a reliable performance metric.

Update Frequency: Daily

See the list of most profitable insider traders.

Companies with Reported Insider Positions

The SEC filings indicate David C Dvorak has reported holdings or trades in the following companies:

Security Title Latest Reported Holdings
US:ZBH / Zimmer Biomet Holdings, Inc. President and CEO, Director 0
US:STJ / St. Jude Medical, Inc. Director 0
How to Interpret the Charts

The following charts show the stock performance of securities subsequent to each open-market, non-planned trade made by David C Dvorak. Non-planned trade are trades that were not made as part of a 10b5-1 trading plan. The stock performance is charted as cumulative percent change in share price. For example, if an insider trade was made on January 1, 2019, the chart will show the daily percent change of the security to the present day. If the share price were to go from $10 to $15 during this time, the cumulative percent change in share price would be 50%. A change in price from $10 to $20 would be 100%, and a change in price of $10 to $5 would be -50%.

Ultimately, we are trying to determine how closely the insider’s trades correlate to excess returns (positive or negative) in the share price in order to see if the insider is timing their trades to profit from insider information. Consider the situation where an insider was doing this. In this situation, we would expect either (a) positive returns after purchases, or (b) negative returns after sales. In the case of (a), the PURCHASE chart would show a series of upwardly sloping curves, indicating positive returns after each purchase transaction. In the case of (b), the SALE chart would show a series of downward sloping curves, indicating negative returns after each sale transaction.

However, this alone is not enough to draw conclusions. If, for example, the share price of the company was in a non-cyclical climb over many years, then we would expect all the post-purchase plots to be upwardly sloping. Likewise, non-cyclical declines over many years would result in downward sloping post-trade plots. Neither of these charts would suggest insider trading activity.

The strongest indicator would be a situation where the share price was extremely cyclical, and there were both positive signals in the PURCHASE chart and negative plots on the SALE chart. This situation would be highly suggestive of an insider that was timing trades to their financial advantage.

Insider Trading History

This table shows the complete list of insider trades made by David C Dvorak as disclosed to the Securities Exchange Commission (SEC).

File Date Tran Date Form Ticker Security Code 10b5-1 Shares Remaining Shares Percent
Change
Share
Price
Tran
Value
Remaining
Value
2017-05-01 2017-04-27 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
M - Exercise -100,000 0 -100.00
2017-05-01 2017-04-27 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -34,547 294,555 -10.50 116.99 -4,041,654 34,459,989
2017-05-01 2017-04-27 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -52,784 329,102 -13.82 116.13 -6,129,806 38,218,615
2017-05-01 2017-04-27 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise X 100,000 381,886 35.48 88.76 8,876,000 33,896,201
2017-03-23 2017-03-21 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
A - Award 145,350 145,350
2017-03-21 2017-03-20 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -1,040 281,886 -0.37 121.63 -126,495 34,285,794
2017-03-21 2017-03-17 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Restricted Stock Units
M - Exercise -23,929 0 -100.00
2017-03-21 2017-03-17 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
F - Taxes -11,151 282,926 -3.79 120.47 -1,343,361 34,084,095
2017-03-21 2017-03-17 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise 23,929 294,077 8.86
2017-02-13 2017-02-09 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Restricted Stock Units
A - Award 23,929 23,929
2017-02-06 2017-02-02 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
M - Exercise -52,500 0 -100.00
2017-02-06 2017-02-02 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -43,207 270,148 -13.79 117.77 -5,088,562 31,815,789
2017-02-06 2017-02-02 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise X 52,500 313,355 20.13 83.68 4,393,200 26,221,546
2017-01-06 2017-01-04 4 STJ ST JUDE MEDICAL, LLC
Common Stock
D - Sale to Issuer -5,599 0 -100.00
2016-06-03 2016-06-01 4 STJ ST JUDE MEDICAL INC
Common Stock
A - Award 1,277 5,599 29.55 78.27 99,951 438,234
2016-05-06 2016-05-04 4 STJ ST JUDE MEDICAL INC
Common Stock
A - Award 2,401 4,322 124.99 75.36 180,939 325,706
2016-03-23 2016-03-21 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
A - Award 177,980 177,980
2016-03-22 2016-03-21 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -1,540 260,586 -0.59 104.16 -160,403 27,142,091
2016-03-22 2016-03-18 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Restricted Stock Units
M - Exercise -32,810 0 -100.00
2016-03-22 2016-03-18 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
F - Taxes -15,290 262,126 -5.51 103.97 -1,589,701 27,253,240
2016-03-22 2016-03-18 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise 32,810 277,416 13.41
2016-03-02 2016-02-29 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Restricted Stock Units
A - Award 32,810 32,810
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
M - Exercise -34,536 0 -100.00
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
M - Exercise -20,464 34,536 -37.21
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -28,424 244,502 -10.41 102.32 -2,908,344 25,017,445
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise X 34,536 272,926 14.49 71.06 2,454,128 19,394,122
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
S - Sale X -16,237 238,390 -6.38 102.71 -1,667,702 24,485,037
2016-01-12 2016-01-08 4 ZBH ZIMMER BIOMET HOLDINGS, INC.
Common Stock
M - Exercise X 20,464 254,627 8.74 71.06 1,454,172 18,093,795
2015-08-06 2015-08-04 4 STJ ST JUDE MEDICAL INC
Common Stock
A - Award 1,921 1,921 72.76 139,772 139,772
2015-08-06 3 STJ ST JUDE MEDICAL INC
Common Stock
0
2015-06-26 2015-06-24 4 ZMH ZIMMER BIOMET HOLDINGS, INC.
Employee Stock Option (right to buy)
A - Award 157,433 157,433
2015-03-23 2015-03-19 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -34,881 0 -100.00
2015-03-23 2015-03-19 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -16,255 234,001 -6.50 118.41 -1,924,755 27,708,058
2015-03-23 2015-03-19 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 34,881 250,256 16.20
2015-03-18 2015-03-17 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale X -1,300 215,375 -0.60 115.55 -150,218 24,887,055
2015-03-18 2015-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -18,722 0 -100.00
2015-03-18 2015-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -7,549 216,675 -3.37 117.44 -886,555 25,446,312
2015-03-18 2015-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 18,722 224,224 9.11
2015-02-23 2015-02-19 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
A - Award 34,881 34,881
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (Right to Buy)
M - Exercise -23,408 0 -100.00
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (Right to Buy)
M - Exercise -34,833 0 -100.00
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale X -19,575 205,377 -8.70 115.00 -2,251,125 23,618,355
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise X 23,408 224,952 11.61 79.60 1,863,160 17,905,054
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale X -29,128 201,544 -12.63 115.00 -3,349,720 23,177,560
2014-12-08 2014-12-05 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise X 34,833 230,672 17.79 79.60 2,772,533 18,360,338
2014-03-19 2014-03-17 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (right to buy)
A - Award 132,390 132,390
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -18,723 18,722 -50.00
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -21,229 0 -100.00
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -7,278 195,670 -3.59 94.96 -691,082 18,579,845
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 18,723 202,948 10.16
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -9,914 184,225 -5.11 94.96 -941,384 17,493,085
2014-03-18 2014-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 21,229 194,139 12.28
2013-11-15 2013-11-14 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (right to buy)
M - Exercise -73,333 0 -100.00
2013-11-15 2013-11-14 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale X -64,763 172,746 -27.27 90.00 -5,828,670 15,547,140
2013-11-15 2013-11-14 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise X 73,333 237,509 44.67 70.32 5,157,143 16,702,820
2013-03-20 2013-03-18 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (right to buy)
A - Award 173,780 173,780
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -18,723 37,445 -33.33
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -21,231 21,229 -50.00
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -8,679 163,953 -5.03 73.82 -640,684 12,103,010
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 18,723 172,632 12.16
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -9,841 153,909 -6.01 73.82 -726,463 11,361,562
2013-03-19 2013-03-16 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 21,231 163,750 14.90
2013-02-20 2013-02-17 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -13,967 0 -100.00
2013-02-20 2013-02-17 4 ZMH ZIMMER HOLDINGS INC
Common Stock
F - Taxes -6,474 142,519 -4.35 75.88 -491,215 10,813,629
2013-02-20 2013-02-17 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 13,967 148,993 10.34
2013-01-09 2013-01-08 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (Right to Buy)
M - Exercise -66,000 0 -100.00
2013-01-09 2013-01-08 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale X -48,812 134,814 -26.58 69.11 -3,373,446 9,317,130
2013-01-09 2013-01-08 4 ZMH ZIMMER HOLDINGS INC
Common Stock
M - Exercise 66,000 183,626 56.11 39.53 2,608,980 7,258,736
2012-05-07 2012-05-03 4 ZMH ZIMMER HOLDINGS INC
Common Stock
S - Sale -3,073 117,368 -2.55 63.97 -196,587 7,508,324
2012-03-21 2012-03-19 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (right to buy)
A - Award 184,230 184,230
2012-03-20 2012-03-16 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -21,231 42,460 -33.33
2012-03-20 2012-03-16 4 ZMH ZIMMER HOLDINGS INC
Common
F - Taxes -8,539 120,441 -6.62 63.94 -545,984 7,700,998
2012-03-20 2012-03-16 4 ZMH ZIMMER HOLDINGS INC
Common
M - Exercise 21,231 128,980 19.70
2012-02-23 2012-02-21 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
A - Award 56,168 56,168
2012-02-22 2012-02-17 4 ZMH ZIMMER HOLDINGS INC
Restricted Stock Units
M - Exercise -13,969 13,967 -50.00
2012-02-22 2012-02-17 4 ZMH ZIMMER HOLDINGS INC
Common
F - Taxes -4,310 107,749 -3.85 61.66 -265,755 6,643,803
2012-02-22 2012-02-17 4 ZMH ZIMMER HOLDINGS INC
Common
M - Exercise 13,969 112,059 14.24
2007-05-02 2007-05-01 4 ZMH ZIMMER HOLDINGS INC
Employee Stock Option (right to buy)
A - Award 100,000 100,000
2007-05-02 2007-05-01 4 ZMH ZIMMER HOLDINGS INC
Common Stock
A - Award 22,532 31,652 247.06
2004-01-16 2004-01-14 4 ZMH ZIMMER HOLDINGS INC
Common Stock
A - Award 7,500 8,075 1,304.35
P
Open market or private purchase of non-derivative or derivative security
S
Open market or private sale of non-derivative or derivative security
A
Grant, award, or other acquisition of securities from the company (such as an option)
C
Conversion of derivative
D
Sale or transfer of securities back to the company
F
Payment of exercise price or tax liability using portion of securities received from the company
G
Gift of securities by or to the insider
K
Equity swaps and similar hedging transactions
M
Exercise or conversion of derivative security received from the company (such as an option)
V
A transaction voluntarily reported on Form 4
J
Other (accompanied by a footnote describing the transaction)