Here is a concise and essential title for the passage provided using a different phrasing: "3 Under-the-Radar Penny Stocks With Market Caps Under $300M: AirJoule Technologies, Apyx Medical, and More"

This article highlights three promising penny stocks with market caps under $300M: Waterdrop (WDH), CuriosityStream (CURI), and WM Technology (MAPS). These stocks have strong financial health ratings and are considered to have potential for growth. Additionally, the article reviews AirJoule Technologies and Apyx Medical Corporation, which have gained attention for their renewable energy and medical technology.

The U.S. stock market has seen significant growth, with major indices like the S&P 500 and Nasdaq Composite reaching new highs. In this context, penny stocks continue to attract interest due to their potential for growth at a lower entry cost. While the term "penny stocks" may seem outdated, these investments in smaller or newer companies can still offer substantial opportunities when backed by solid financials.

Waterdrop (WDH), CuriosityStream (CURI), and WM Technology (MAPS) are three notable penny stocks with market caps under $300M. These companies have strong financial health ratings and are considered to have potential for growth.

Waterdrop (WDH) is a water technology company with a market cap of $737.79M. The company specializes in water purification and filtration technologies. It has a financial health rating of ★★★★★☆, indicating a robust financial position. Waterdrop has shown positive growth in its share price and market cap, making it an attractive option for investors seeking growth potential.

CuriosityStream (CURI) is a streaming service provider with a market cap of $275.27M. The company offers a subscription-based service that provides access to educational content. CuriosityStream has a financial health rating of ★★★★★☆, indicating a strong financial position. The company has shown consistent growth in its share price and market cap, making it a promising investment.

WM Technology (MAPS) is a technology company with a market cap of $163.33M. The company specializes in manufacturing and selling water purification systems. WM Technology has a financial health rating of ★★★★☆☆, indicating a solid financial position. The company has shown positive growth in its share price and market cap, making it an attractive investment option.

In addition to these penny stocks, AirJoule Technologies and Apyx Medical Corporation have gained attention for their renewable energy and medical technology. AirJoule Technologies specializes in atmospheric renewable energy and water harvesting technology, with a market cap of $276.48M. The company has been gaining attention for its innovative technology and strategic moves towards operational resilience and innovation in sustainable water solutions. Apyx Medical Corporation is an energy technology company that designs, develops, manufactures, and sells electrosurgical equipment and medical devices. The company has a market cap of $95.99M and has shown strong revenue growth and financial stability.

These companies represent promising opportunities for investors seeking growth potential in the penny stock market. However, it is essential to conduct thorough research and analysis before making any investment decisions. The financial health ratings and market caps provided in this article serve as a starting point for further investigation.

References:
[1] https://simplywall.st/stocks/us/media/nasdaq-trvg/trivago/news/3-promising-penny-stocks-with-market-caps-under-300m-1
[2] https://www.theglobeandmail.com/investing/markets/stocks/MSFT/pressreleases/33687446/3-no-brainer-energy-stocks-to-buy-with-500-right-now/