Century Aluminum Company
US ˙ NasdaqGS ˙ US1564311082

Introduction

This page provides a comprehensive analysis of the known insider trading history of Andrew G Michelmore. 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 Andrew G Michelmore has reported holdings or trades in the following companies:

Security Title Latest Reported Holdings
US:CENX / Century Aluminum Company Director 89,089
How to Interpret the Charts

The following charts show the stock performance of securities subsequent to each open-market, non-planned trade made by Andrew G Michelmore. 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 Purchases CENX / Century Aluminum Company - Short Term Profit Analysis

In this section, we analyze the profitability of every unplanned, open-market insider purchase made in CENX / Century Aluminum Company. This analysis helps to understand if the insider consistently generates abnormal returns, and is worth following. This analysis is for one-year following each trade, and the results are theoretical.

The following table shows the most recent open market purchases that were not part of an automatic trading plan.

Trade Date Ticker Insider Reported
Shares
Reported
Price
Adjusted
Shares
Adjusted
Price
Cost Basis Days to
Max
Price at
Max
Max
Profit ($)
Max Return (%)
2020-03-10 CENX Michelmore Andrew G 3,000 4.4100 3,000 4.4100 13,230 365 18.4100 42,000 317.46
2019-06-13 CENX Michelmore Andrew G 5,000 5.7800 5,000 5.7800 28,900
2018-10-29 CENX Michelmore Andrew G 5,000 7.8700 5,000 7.8700 39,350

Adjusted Price is the split-adjusted price. Adjusted Shares is the split-adjusted shares.

CENX / Century Aluminum Company Insider Trades
Insider Sales CENX / Century Aluminum Company - Short Term Loss Analysis

In this section, we analyze the short-term loss avoidance of every unplanned, open-market insider sale made in CENX / Century Aluminum Company. A consistent pattern of loss avoidance may suggest that future sale transactions may predict declines in price. This analysis is for one-year following each trade, and the results are theoretical.

The following table shows the most recent open market sales that were not part of an automatic trading plan.

Trade Date Ticker Insider Reported
Shares
Reported
Price
Adjusted
Shares
Adjusted
Price
Cost Basis Days to
Min
Price at
Min
Max Loss
Avoided ($)
Max Loss
Avoided (%)
There are no known unplanned open-market trades for this insider and security combination

Adjusted Price is the split-adjusted price. Adjusted Shares is the split-adjusted shares.

CENX / Century Aluminum Company Insider Trades
Insider Trading History

This table shows the complete list of insider trades made by Andrew G Michelmore 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
2025-06-18 2025-06-16 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,333 89,089 -2.55 17.36 -40,501 1,546,585
2025-06-18 2025-06-16 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 7,778 91,422 9.30
2024-06-05 2024-06-03 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,121 83,644 -2.47 17.71 -37,563 1,481,335
2024-06-05 2024-06-03 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 7,070 85,765 8.98
2023-06-07 2023-06-05 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -4,448 78,695 -5.35 8.51 -37,852 669,694
2023-06-07 2023-06-05 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 14,825 83,143 21.70
2022-06-16 2022-06-14 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,808 68,318 -3.95 10.43 -29,287 712,557
2022-06-16 2022-06-14 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 9,358 71,126 15.15
2021-06-16 2021-06-15 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,321 61,768 -3.62 13.42 -31,148 828,927
2021-06-16 2021-06-15 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 7,737 64,089 13.73
2020-06-11 2020-06-09 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -5,466 56,352 -8.84 7.83 -42,799 441,236
2020-06-11 2020-06-09 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 18,220 61,818 41.79
2020-03-11 2020-03-10 4 CENX CENTURY ALUMINUM CO
Common Stock
P - Purchase 3,000 43,598 7.39 4.41 13,230 192,267
2019-06-20 2019-06-13 4 CENX CENTURY ALUMINUM CO
Common Stock
P - Purchase 5,000 40,598 14.05 5.78 28,900 234,656
2019-06-05 2019-06-04 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -3,879 35,598 -9.83 5.63 -21,839 200,417
2019-06-05 2019-06-04 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 12,929 39,477 48.70
2018-10-31 2018-10-29 4 CENX CENTURY ALUMINUM CO
Common Stock
P - Purchase 5,000 26,548 23.20 7.87 39,350 208,933
2018-09-19 3 CENX CENTURY ALUMINUM CO
Common Stock
33,326
2018-09-19 3 CENX CENTURY ALUMINUM CO
Common Stock
33,326
2018-09-19 3 CENX CENTURY ALUMINUM CO
Common Stock
33,326
2018-09-19 2018-09-17 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -1,766 21,548 -7.57 11.78 -20,803 253,835
2018-09-19 2018-09-17 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 5,885 23,314 33.77
2015-09-02 2015-08-31 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,419 27,429 -8.10 5.60 -13,546 153,602
2014-09-10 2014-09-09 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 3,495 29,848 13.26
2014-09-10 2014-09-08 4 CENX CENTURY ALUMINUM CO
Common Stock
F - Taxes -2,702 26,353 -9.30 28.47 -76,926 750,270
2013-09-26 2013-09-24 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 9,004 29,055 44.91
2013-09-23 2013-09-19 4 CENX CENTURY ALUMINUM CO
Common Stock
D - Sale to Issuer -3,324 20,051 -14.22
2012-09-21 2012-09-19 4 CENX CENTURY ALUMINUM CO
Common Stock
A - Award 11,078 23,375 90.09
2010-06-11 3 CENX CENTURY ALUMINUM CO
Common Stock
0
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)