Rubico Inc.
US ˙ NasdaqCM ˙ US78112V1026

Introduction

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

Security Title Latest Reported Holdings
US:MGNI / Magnite, Inc. CHIEF ACCOUNTING OFFICER 92,898
Chief Financial Officer 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 Brian Gephart. 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 RUBI / Rubico Inc. - Short Term Profit Analysis

In this section, we analyze the profitability of every unplanned, open-market insider purchase made in RUBI / Rubico Inc.. 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 (%)
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.

RUBI / Rubico Inc. Insider Trades
Insider Sales RUBI / Rubico Inc. - Short Term Loss Analysis

In this section, we analyze the short-term loss avoidance of every unplanned, open-market insider sale made in RUBI / Rubico Inc.. 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 (%)
2025-08-18 MGNI Gephart Brian 2,961 23.8500 2,961 23.8500 70,620 1 21.8400 -5,951 -8.43
2025-05-12 MGNI Gephart Brian 6,334 16.1600 6,334 16.1600 102,357
2025-03-03 MGNI Gephart Brian 6,250 16.0000 6,250 16.0000 100,000
2023-08-16 MGNI Gephart Brian 1,141 8.3100 1,141 8.3100 9,482
2023-05-16 MGNI Gephart Brian 1,237 10.8800 1,237 10.8800 13,459

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

RUBI / Rubico Inc. Insider Trades
Insider Trading History

This table shows the complete list of insider trades made by Brian Gephart 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
2025-09-05 2025-09-04 4 MGNI MAGNITE, INC.
Common Stock
S - Sale X -27,671 92,898 -22.95 24.71 -683,750 2,295,510
2025-08-20 2025-08-18 4 MGNI MAGNITE, INC.
Common Stock
S - Sale -2,961 120,569 -2.40 23.85 -70,620 2,875,571
2025-05-16 2025-05-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -3,045 123,530 -2.41 15.88 -48,355 1,961,656
2025-05-14 2025-05-12 4 MGNI MAGNITE, INC.
Common Stock
S - Sale -6,334 126,575 -4.77 16.16 -102,357 2,045,452
2025-03-05 2025-03-03 4 MGNI MAGNITE, INC.
Common Stock
S - Sale -6,250 132,909 -4.49 16.00 -100,000 2,126,544
2025-02-19 2025-02-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -6,749 139,159 -4.63 20.00 -134,980 2,783,180
2025-01-06 2025-01-02 4 MGNI MAGNITE, INC.
Common Stock
A - Award 33,113 145,908 29.36
2024-11-19 2024-11-18 4 MGNI MAGNITE, INC.
Common Stock
S - Sale X -2,156 112,795 -1.88 15.60 -33,634 1,759,602
2024-11-19 2024-11-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -2,031 114,951 -1.74 15.85 -32,191 1,821,973
2024-11-13 2024-11-11 4 MGNI MAGNITE, INC.
Common Stock
S - Sale X -2,156 116,982 -1.81 15.00 -32,340 1,754,730
2024-08-16 2024-08-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -2,031 119,138 -1.68 12.51 -25,408 1,490,416
2024-07-17 2024-07-15 4 MGNI MAGNITE, INC.
Common Stock
S - Sale X -16,166 121,169 -11.77 15.00 -242,490 1,817,535
2024-05-17 2024-05-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -2,004 137,335 -1.44 9.80 -19,639 1,345,883
2024-02-16 2024-02-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -5,650 139,339 -3.90 9.74 -55,031 1,357,162
2024-01-04 2024-01-02 4 MGNI MAGNITE, INC.
Common Stock
A - Award 50,667 144,989 53.72
2023-11-17 2023-11-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -1,100 94,322 -1.15 7.89 -8,679 744,201
2023-08-18 2023-08-16 4 MGNI MAGNITE, INC.
Common Stock
S - Sale -1,141 95,422 -1.18 8.31 -9,482 792,957
2023-05-18 2023-05-16 4 MGNI MAGNITE, INC.
Common Stock
S - Sale -1,237 96,563 -1.26 10.88 -13,459 1,050,605
2023-02-17 2023-02-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -3,850 97,800 -3.79 13.27 -51,090 1,297,806
2023-01-04 2023-01-01 4 MGNI MAGNITE, INC.
Common Stock
A - Award 45,167 101,650 79.97
2022-11-17 2022-11-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -366 56,483 -0.64 11.47 -4,198 647,860
2022-08-17 2022-08-15 4 MGNI MAGNITE, INC.
Common Stock
F - Taxes -1,712 56,849 -2.92 9.80 -16,778 557,120
2022-02-03 2022-02-01 4 MGNI MAGNITE, INC.
Common Stock
A - Award 38,036 56,304 208.21
2021-07-02 2021-07-01 4 MGNI MAGNITE, INC.
Stock Option (Right to Buy)
A - Award 13,594 13,594
2021-07-02 2021-07-01 4 MGNI MAGNITE, INC.
Common Stock
A - Award 18,268 18,268
2021-06-16 2021-06-14 4 LEAF LEAF GROUP LTD.
Common Stock
D - Sale to Issuer -123,988 0 -100.00
2021-06-02 2021-06-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -578 123,988 -0.46 8.46 -4,890 1,048,938
2021-05-03 2021-05-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -578 124,566 -0.46 8.86 -5,121 1,103,655
2021-04-02 2021-04-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -3,701 125,144 -2.87 7.03 -26,018 879,762
2021-03-03 2021-03-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -343 128,845 -0.27 5.27 -1,808 679,013
2021-02-03 2021-02-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -343 129,188 -0.26 5.90 -2,024 762,209
2021-01-05 2021-01-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -343 129,531 -0.26 4.65 -1,595 602,319
2020-12-02 2020-12-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -340 129,874 -0.26 5.34 -1,816 693,527
2020-11-03 2020-11-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -340 130,215 -0.26 5.70 -1,938 742,226
2020-10-20 2020-10-16 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
A - Award 10,000 130,555 8.29
2020-10-05 2020-10-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -341 120,555 -0.28 5.54 -1,889 667,875
2020-09-03 2020-09-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -289 120,896 -0.24 4.85 -1,402 586,346
2020-08-04 2020-08-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -289 121,184 -0.24 5.13 -1,483 621,674
2020-07-31 2020-07-29 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
A - Award 65,000 121,473 115.10
2020-07-06 2020-07-01 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
F - Taxes -3,527 56,473 -5.88 4.04 -14,249 228,151
2020-06-25 2020-06-18 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
A - Award 30,000 60,000 100.00
2019-08-02 2019-07-24 4 LEAF LEAF GROUP LTD.
Common Stock, $.0001 par value
A - Award 30,000 30,000
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)