NASDAQ:SPRO

Spero Therapeutics Stock Insider Trading

Healthcare > Biotechnology

Buy SPRO

*Your capital is at risk

$2.80

-0.0300 (-1.06%)

At Close: Jun 03, 2026

Spero Therapeutics Stock Insider Power

Based on the 100 latest insides trades, we have calculated the insider power to be negative at -37.48. In total, the insiders bought 5.69M and sold 1.25M SPRO 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)	-37.48
● Buy	5.69M shares
● Sell	1.25M shares
50% Buy Activity Moderate Positive Correlation
Sell Signal Medium Confidence Feb 06, 2026 Analysis Breakdown: Supported by a negative Insider Power Score of -37.48. Partially supported by a positive historical correlation. Confidence increased due to high data reliability score of 100.

Historical Insider Trades

Date	Type	Person	Role	Amount
May 04, 2026 Sell	Common Stock S-Sale	Rajavelu Esther See Remarks	Officer	25 240 Value: $63.4K
Feb 06, 2026 Sell	Common Stock S-Sale	Rajavelu Esther See Remarks	Officer	50 816 Value: $119.9K
Feb 06, 2026 Sell	Common Stock S-Sale	Rajavelu Esther See Remarks	Officer	37 101 Value: $87.6K
Feb 06, 2026 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	18 652 Value: $44.0K
Feb 04, 2026 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	3 471 Value: $8K
Feb 03, 2026 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	24 224 Value: $51.8K
Feb 02, 2026 Buy	Stock Option (Right to Buy) A-Award	Keutzer Timothy Chief Operating Officer	C-Suite Officer	137 000 Value: $305.5K
Feb 02, 2026 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	18 891 Value: $41.6K
Feb 02, 2026 Buy	Common Stock A-Award	Keutzer Timothy Chief Operating Officer	C-Suite Officer	68 000 Value: $151.6K
Feb 02, 2026 Buy	Stock Option (Right to Buy) A-Award	Rajavelu Esther See Remarks	Officer	498 000 Value: $1.11M
Feb 02, 2026 Buy	Common Stock A-Award	Rajavelu Esther See Remarks	Officer	249 000 Value: $555.3K
Feb 02, 2026 Sell	Common Stock S-Sale	Rajavelu Esther See Remarks	Officer	18 442 Value: $40.6K
Nov 07, 2025 Sell	Common Stock S-Sale	Rajavelu Esther See Remarks	Officer	40 270 Value: $95.4K
Aug 28, 2025 Sell	Common Stock S-Sale	Mahadevia Ankit Director	Director	6 572 Value: $12.9K
Aug 28, 2025 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	1 695 Value: $3K
Aug 28, 2025 Sell	Common Stock S-Sale	Keutzer Timothy Chief Operating Officer	C-Suite Officer	1 695 Value: $3K
Aug 28, 2025 Sell	Common Stock S-Sale	Mahadevia Ankit Director	Director	6 572 Value: $12.9K
Jun 12, 2025 Buy	Common Stock A-Award	Mahadevia Ankit Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Deshpande Milind Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Jackson Scott Thomas Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Vink Patrick V.j.j. Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Pottage John C Jr Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Smith Cynthia Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Thomas Frank E Director	Director	20 000 Value: $57.8K
Jun 12, 2025 Buy	Common Stock A-Award	Tregoning Kathleen Director	Director	20 000 Value: $57.8K

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

ABOUT SPERO THERAPEUTICS INC.

Spero Therapeutics, Inc., a clinical-stage biopharmaceutical company, focuses on identifying, developing, and commercializing treatments for multi-drug resistant (MDR) bacterial infections and rare diseases in the United States. The company's product candidates include tebipenem pivoxil hydrobromide (HBr), an oral carbapenem-class antibiotic to treat complicated urinary tract infections, including pyelonephritis for adults; SPR206, a direct actin...

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