89bio Stock Insider Trading

Healthcare > Biotechnology

Buy ETNB

*Your capital is at risk

$14.84

+0 (+0%)

At Close: Jan 29, 2026

89bio Stock Insider Power

Based on the 100 latest insides trades, we have calculated the insider power to be negative at -96.02. In total, the insiders bought 421.6K and sold 13.45M ETNB shares in the last 100 trades. The insider score can be negative despite buy/sell ratio being positive. The score focuses on the quality of the trades.

Insider Power (Last 100 transactions)	-96.02
● Buy	421.6K shares
● Sell	13.45M shares
8% Buy Activity Weak Negative Correlation
Sell Signal High Confidence Oct 30, 2025 Analysis Breakdown: Strongly supported by a very low Insider Power Score of -96.02. Confidence increased due to high data reliability score of 100. Supported by overwhelming sell-side pressure (8% buys).

Historical Insider Trades

Date	Type	Person	Role	Amount
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	12 500 Value: $302.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	7 000 Value: $170.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	7 000 Value: $149.8K
Oct 30, 2025 Sell	Pre-Funded Warrants (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	4 331 081 Value: $4K
Oct 30, 2025 Sell	Common Stock D-Return	Ra Capital Management, L.p.	Director	335 364 Value: $4.86M
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	25 000 Value: $66.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	27 400 Value: $402.8K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	45 150 Value: $450.6K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Ra Capital Management, L.p.	Director	56 400 Value: $541.4K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Mansbach Harry H Chief Medical Officer	Officer	320 000 Value: $3.07M
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Mansbach Harry H Chief Medical Officer	Officer	195 000 Value: $1.95M
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Mansbach Harry H Chief Medical Officer	Officer	70 000 Value: $310.8K
Oct 30, 2025 Sell	Common Stock U-Tender	Mansbach Harry H Chief Medical Officer	Officer	352 656 Value: $5.11M
Oct 30, 2025 Buy	Common Stock A-Award	Mansbach Harry H Chief Medical Officer	Officer	50 000 Value: $742.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Sarena Francis Willard Chief Operating Officer	C-Suite Officer	215 000 Value: $2.06M
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Sarena Francis Willard Chief Operating Officer	C-Suite Officer	350 000 Value: $2.94M
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	56 400 Value: $541.4K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Le-nguyen Quoc See Remarks	Officer	3 312 Value: $10.3K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	45 150 Value: $450.6K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	27 400 Value: $402.8K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	25 000 Value: $66.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	12 500 Value: $302.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	7 000 Value: $170.0K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Dirocco Derek Director	Director	7 000 Value: $149.8K
Oct 30, 2025 Sell	Stock Option (Right to Buy) D-Return	Babler Martin Director	Director	56 400 Value: $541.4K

About Insider Power

Insider Power is a proprietary algorithm developed by StockInvest.us to evaluate the significance of insider transactions. The calculation considers the size, type, and timing of transactions, as well as the insider’s role within the company.

It is important to note that, in general, there is little to no correlation between insider transactions and short-term stock price movements. In one of our studies, only 0.22%^* of stocks with insider activity showed a measurable correlation — and even then, it was unclear whether the effect was caused by insider actions or simply by the stock’s broader trend.

While our algorithms are designed to highlight potentially meaningful signals, these cannot be regarded as statistically significant on their own. Insider trading activity should therefore be seen as informative rather than as direct trading guidance. The Insider Power metric was created to present this information in a clearer and more accessible way, helping investors better understand the possible context of insider activity.

* October 6th, 2025 - Tested on 5562 stocks