The Dow Jones index closed higher by around 250 points on Tuesday. When insiders purchase or sell shares, it indicates their confidence or concern around the company's prospects. Investors and traders interested in penny stocks can consider this a factor in their overall investment or trading decision.

Below is a look at a few recent notable insider transactions for penny stocks. For more, check out Benzinga's insider transactions platform.

Cyanotech

• The Trade: Cyanotech Corporation (NASDAQ:CYAN) Director Michael Davis acquired a total of 400,000 shares an average price of $1.00. To acquire these shares, it cost around $400,000.
• What's Happening: On Nov. 8, Cyanotech posted a narrower loss for the second quarter.
• What Cyanotech Does: Cyanotech Corp is engaged in the production of natural products derived from microalgae for the nutritional supplements market.

BioAtla

• The Trade: BioAtla, Inc. (NASDAQ:BCAB) Director Lawrence Steinman acquired a total of 20,000 shares at an average price of $2.05. To acquire these shares, it cost around $41,048.
• What's Happening: BioAtla, last month, said net loss for the third quarter was $33.3 million, versus a year-ago net loss of $25.8 million.
• What BioAtla Does: BioAtla Inc is a clinical-stage biopharmaceutical company. The company is engaged in the development of a novel class of highly specific and selective antibody-based therapeutics for the treatment of solid tumor cancer.

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Beyond Air

• The Trade: Beyond Air, Inc. (NASDAQ:XAIR) Director Robert Carey acquired a total of 1,200,000 shares at an average price of $1.64. The insider spent around $1.96 million to buy those shares. The company's CEO and Chairman of the Board also bought 77,775 shares of the company.
• What's Happening: On Nov. 13, Beyond Air posted downbeat quarterly results.
• What Beyond Air Does: Beyond Air Inc is a clinical-stage medical device and biopharmaceutical company that develops a Nitric Oxide (NO) Generator and Delivery System that uses NO generated from ambient air and delivers precise amounts of NO to the lungs for the potential treatment of respiratory and other diseases.

Cardiff Oncology

• The Trade: Cardiff Oncology, Inc. (NASDAQ:CRDF) Director Gary Pace acquired a total of 30,000 shares at an average price of $1.37. The insider spent around $41,100 to buy those shares.
• What's Happening: On Nov. 2, Cardiff Oncology posted upbeat quarterly results.
• What Cardiff Oncology Does: Cardiff Oncology Inc is a clinical-stage, biotechnology company, developing treatment options for cancer patients in indications with the greatest medical need, including KRAS-mutated metastatic colorectal cancer, pancreatic cancer, metastatic castrate-resistant prostate cancer and leukemias.

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