89bio, Inc.
US ˙ NasdaqGM ˙ US2825591033

Introduction

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

Security Title Latest Reported Holdings
US:ETNB / 89bio, Inc. Director 25,000
US:CBAY / CymaBay Therapeutics, Inc. President of R&D 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 Charles McWherter. 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 ETNB / 89bio, Inc. - Short Term Profit Analysis

In this section, we analyze the profitability of every unplanned, open-market insider purchase made in ETNB / 89bio, 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 (%)
2025-01-22 ETNB McWherter Charles 10,000 6.7100 10,000 6.7100 67,100 14 11.6600 49,500 73.77
2025-01-21 ETNB McWherter Charles 5,000 6.5500 5,000 6.5500 32,750
2024-12-05 ETNB McWherter Charles 10,000 8.0000 10,000 8.0000 80,000

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

ETNB / 89bio, Inc. Insider Trades
Insider Sales ETNB / 89bio, Inc. - Short Term Loss Analysis

In this section, we analyze the short-term loss avoidance of every unplanned, open-market insider sale made in ETNB / 89bio, 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 (%)
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.

ETNB / 89bio, Inc. Insider Trades
Insider Trading History

This table shows the complete list of insider trades made by Charles McWherter 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
2025-01-23 2025-01-22 4 ETNB 89bio, Inc.
Common Stock
P - Purchase 10,000 25,000 66.67 6.71 67,100 167,750
2025-01-23 2025-01-21 4 ETNB 89bio, Inc.
Common Stock
P - Purchase 5,000 15,000 50.00 6.55 32,750 98,250
2024-12-09 2024-12-05 4 ETNB 89bio, Inc.
Common Stock
P - Purchase 10,000 10,000 8.00 80,000 80,000
2024-03-22 2024-03-22 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
D - Sale to Issuer -31,938 0 -100.00
2024-03-22 2024-03-22 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
D - Sale to Issuer -15,000 0 -100.00
2024-01-26 2024-01-24 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
A - Award 31,938 46,938 212.92
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -3,125 15,000 -17.24 23.68 -73,988 355,140
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 3,125 18,125 20.83 11.69 36,531 211,881
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -8,334 15,000 -35.72 23.68 -197,316 355,140
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 8,334 23,334 55.56 10.00 83,340 233,340
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -1,916 15,000 -11.33 23.66 -45,340 354,962
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 1,916 16,916 12.77 1.82 3,487 30,787
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -2,778 15,000 -15.63 23.66 -65,739 354,962
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 2,778 17,778 18.52 1.72 4,778 30,578
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -2,250 15,000 -13.04 23.67 -53,262 355,082
2024-01-22 2024-01-19 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 2,250 17,250 15.00 1.06 2,385 18,285
2023-12-18 2023-12-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -6,504 15,000 -30.25 21.48 -139,703 322,194
2023-12-18 2023-12-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 6,504 21,504 43.36 5.00 32,520 107,520
2023-12-18 2023-12-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -4,828 15,000 -24.35 21.49 -103,738 322,300
2023-12-18 2023-12-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 4,828 19,828 32.19 5.00 24,140 99,140
2023-11-17 2023-11-17 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -11,342 15,000 -43.06 18.28 -207,293 274,149
2023-11-17 2023-11-17 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 11,342 26,342 75.61 5.00 56,710 131,710
2023-10-18 2023-10-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,743 15,000 -59.18 14.07 -305,941 211,062
2023-10-18 2023-10-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,743 36,743 144.95 5.00 108,715 183,715
2023-09-19 2023-09-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,746 15,000 -59.18 16.22 -352,733 243,309
2023-09-19 2023-09-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,746 36,746 144.97 5.00 108,730 183,730
2023-08-18 2023-08-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,746 15,000 -59.18 11.47 -249,359 172,004
2023-08-18 2023-08-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,746 36,746 144.97 5.00 108,730 183,730
2023-07-19 2023-07-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,749 15,000 -59.18 11.43 -248,519 171,400
2023-07-19 2023-07-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,749 36,749 144.99 5.00 108,745 183,745
2023-06-21 2023-06-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,749 15,000 -59.18 8.16 -177,383 122,338
2023-06-21 2023-06-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,749 36,749 144.99 5.00 108,745 183,745
2023-05-19 2023-05-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
S - Sale X -21,749 15,000 -59.18 9.08 -197,387 136,136
2023-05-19 2023-05-18 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
M - Exercise 21,749 36,749 144.99 5.00 108,745 183,745
2022-01-27 2022-01-25 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 225,000 225,000
2021-01-28 2021-01-26 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 112,000 112,000
2020-05-19 2020-05-15 4 CBAY CymaBay Therapeutics, Inc.
Stock Option (Right to Buy)
A - Award 328,299 328,299
2019-01-31 2019-01-29 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 172,891 172,891
2018-01-26 2018-01-24 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 150,000 150,000
2017-11-06 2017-11-02 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 4,700 15,000 45.63 8.67 40,740 130,020
2017-11-06 2017-11-02 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 300 10,300 3.00 8.67 2,601 89,301
2017-07-24 2017-07-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 1,700 10,000 20.48 7.43 12,629 74,290
2017-07-24 2017-07-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 200 8,300 2.47 7.43 1,486 61,652
2017-07-24 2017-07-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 3,000 8,100 58.82 7.43 22,280 60,157
2017-07-24 2017-07-20 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 100 5,100 2.00 7.42 742 37,842
2017-01-23 2017-01-19 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 100,000 100,000
2017-01-06 2017-01-04 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 23,000 46,000 100.00
2017-01-04 2016-12-30 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 23,000 23,000
2016-04-19 2016-04-15 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 3,000 5,000 150.00 1.68 5,040 8,400
2016-01-28 2016-01-26 4 CBAY CymaBay Therapeutics, Inc.
Employee Stock Option (right to buy)
A - Award 54,000 54,000
2015-05-19 2015-05-15 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 1,000 2,000 100.00 3.16 3,161 6,322
2015-05-19 2015-05-15 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 600 1,000 150.00 3.17 1,901 3,169
2015-05-19 2015-05-15 4 CBAY CymaBay Therapeutics, Inc.
Common Stock
P - Purchase 400 400 3.14 1,256 1,256
2015-01-08 2015-01-07 4 CBAY CymaBay Therapeutics, Inc.
Stock Option (right to buy)
A - Award 100,000 100,000
2014-01-08 2014-01-06 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
A - Award 52,046 52,046
2013-12-27 2013-12-23 4 NONE CymaBay Therapeutics, Inc.
Stock Appreciation Right
A - Award 31,134 31,134
2013-12-27 2013-12-23 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
A - Award 1,886 1,886
2013-12-27 2013-12-23 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
D - Sale to Issuer -1,886 0 -100.00
2013-12-27 2013-12-23 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
A - Award 5,660 5,660
2013-12-27 2013-12-23 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
D - Sale to Issuer -5,660 0 -100.00
2013-11-01 2013-10-31 4 NONE CymaBay Therapeutics, Inc.
Stock Option (right to buy)
A - Award 62,430 62,430
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)